Name

YANAGITANI, Takahiko

Official Title

Associate Professor

Affiliation

(School of Advanced Science and Engineering)

Contact Information

Mail Address

Mail Address
yanagitani@waseda.jp

URL

Web Page URL

http://www.eb.waseda.ac.jp/yanagitani/

Grant-in-aids for Scientific Researcher Number
10450652

Sub-affiliation

Sub-affiliation

Faculty of Science and Engineering(Graduate School of Advanced Science and Engineering)

Affiliated Institutes

構造生物・創薬研究所

研究所員 2015-

アンビエントロニクス研究所

研究所員 2018-

理工学術院総合研究所(理工学研究所)

兼任研究員 2018-

Educational background・Degree

Educational background

-2001 Doshisha University Faculty of Engineering
-2003 Doshisha University Graduate School, Division of Engineering
-2006 Doshisha University Graduate School, Division of Engineering

Award

Young Scientist Presentation Awar

2015/09

Young Scientist Presentation Award

2013/09

Research Field

Grants-in-Aid for Scientific Research classification

Engineering / Electrical and electronic engineering / Electron device/Electronic equipment

Interdisciplinary science and engineering / Applied physics / Thin film/Surface and interfacial physical properties

Interdisciplinary science and engineering / Applied physics / General applied physics

Interdisciplinary science and engineering / Nano/Micro science / Nano/Microsystems

Interdisciplinary science and engineering / Nano/Micro science / Nanobioscience

Paper

Method for measuring polarity-inverted layered structure in dielectric thin films using scanning nonlinear dielectric microscopy

H. Odagawa, K. Terada, H. Nishikawa, T. Yanagitani and Y. Cho

Ferroelectrics Peer Review Yes 498p.47 - 512016/05-

Detail

Publish Classification:Research paper (scientific journal)

Acoustic wave velocities and refractive indices in an m-plane GaN single crystal plate and c-axis oriented ScAlN films measured by Brillouin scattering techniques

H. Ichihashi T. Yanagitani, M. Suzuki, S. Takayanagi, M. Kawabe, S. Tomita and M. Matsukawa

IEEE Trans. Ultrason., Ferroelectr., Freq. Contr. Peer Review Yes 63(5) p.717 - 7252016/05-

Detail

Publish Classification:Research paper (scientific journal)

High-Tc/high-coupling relaxed PZT-based single crystal thin films

K. Wasa, T. Matsushima, H. Adachi, T. Matsunaga, T. Yanagitani and T. Yamamoto

J. Appl. Phys. Peer Review Yes 117p.1241062015/03-

Detail

Publish Classification:Research paper (scientific journal)

Effects of microstructure and water on the electrical potentials in bone induced by ultrasound irradiation

H Tsuneda, S Matsukawa, S Takayanagi, K Mizuno, T Yanagitani, M Matsukawa

Appl. Phys. Lett. Peer Review Yes 106(7) p.0737042015/02-

Detail

Publish Classification:Research paper (scientific journal)

Gigahertz acoustic wave velocity measurement in GaN single crystals considering acousto-electric effect

H Ichihashi, T Yanagitani, S Takayanagi, M Kawabe, M Matsukawa

IEEE Trans. Ultrason., Ferroelectr., Freq. Contr. Peer Review Yes 61p.1307 - 13132014/08-

Detail

Publish Classification:Research paper (scientific journal)

Electromechanical coupling and gigahertz elastic properties of ScAlN films near phase boundary

T Yanagitani, M Suzuki

Appl. Phys. Lett. Peer Review Yes 105(12) p.1229072014/09-

Detail

Publish Classification:Research paper (scientific journal)

Polarity-inverted ScAlN film growth by ion beam irradiation and application to overtone acoustic wave (000-1)/(0001) film resonators

M. Suzuki, T. Yanagitani, and H. Odagawa

Appl. Phys. Lett. Peer Review Yes 104(23) p.1729052014/05-

Detail

Publish Classification:Research paper (scientific journal)

Enhanced piezoelectricity in YbGaN films near phase boundary

T. Yanagitani, and M. Suzuki

Appl. Phys. Lett. Peer Review Yes 104(23) p.0829112014/02-

Detail

Publish Classification:Research paper (scientific journal)

M. Okino et al., "Electrical potentials in bone induced by ultrasound irradiation in the MHz range"

M. Okino, S. Coutelou, K. Mizuno, T. Yanagitani, M. Matsukawa

Appl. Phys. Lett. Peer Review Yes 103p.1037012013/09-

Detail

Publish Classification:Research paper (scientific journal)

T. Yanagitani and M. Suzuki, "Significant shear mode softening in a c-axis tilt nanostructured hexagonal thin film induced by self-shadowing effect"

T. Yanagitani and M. Suzuki

Scripta mater. Peer Review Yes 69p.724 - 7272013/08-

Detail

Publish Classification:Research paper (scientific journal)

S. Takayanagi, T. Yanagitani and M. Matsukawa, A method for predicting thickness of unoriented layer in ZnO film using piezoelectricity distribution in depth direction

S. Takayanagi, T. Yanagitani and M. Matsukawa

J. Phys. D: Appl. Phys Peer Review Yes 46(315305) p.1 - 52013/07-

Detail

Publish Classification:Research paper (scientific journal)

H. Sano et. al., "High-performance Brillouin spectroscopy of phonons induced by a piezoelectric thin film with a coaxial microwave resonator

H. Sano, T. Yanagitani, S. Takayanagi, T. Sugimoto, M. Matsukawa

IEEE Trans. Ultrason., Ferroelect., Freq. Contr., Peer Review Yes 60(5) p.873 - 8762013/05-

Detail

Publish Classification:Research paper (scientific journal)

S. Takayanagi et. al., Effect of metal mode and oxide mode on unusual c-axis parallel oriented ZnO film growth on Al/glass substrate in a reactive magnetron sputteringo f Zn target

S. Takayanagi, T. Yanagitani, M. Matsukawa

J. Cryst. Growth Peer Review Yes 363p.22 - 242013/01-

Detail

Publish Classification:Research paper (scientific journal)

S. Takayanagi, et. al., Unusual growth of polycrystalline oxide film induced by negative ion bombardment in the capacitively coupled plasma deposition

S. Takayanagi, T. Yanagitani, and M. Matsukawa

Appl. Phys. Lett. Peer Review Yes 101(232902) p.1 - 32012/12-

Detail

Publish Classification:Research paper (scientific journal)

S. Takayanagi et. al., Wideband multimode transducer consisting of c-axis tilted ZnO / caxis normal ZnO multilayer

S. Takayanagi, T. Yanagitani, M. Matsukawa

Jpn. J. Appl. Phys. Peer Review Yes 51(07GC08) 2012/07-

Detail

Publish Classification:Research paper (scientific journal)

K. Yamamoto et al., Relationships between the anisotropy of longitudinal wave velocity and hydroxyapatite crystallite orientation in bovine cortical bone

Kazufumi Yamamoto, M.D.; Tomohiro Nakatsuji; Yuichiro Yaoi; Yu Yamato; Takahiko Yanagitani; Kaoru Yamazaki; Mami Matsukawa; Yukihiro Matsuyama

Ultrasonics Peer Review Yes 52(3) p.377 - 3862011/09-

Detail

Publish Classification:Research paper (scientific journal)

T. Nakatsuji, et al., "Three-Dimensional Anisotropy of Ultrasonic Wave Velocity in Bovine Cortical Bone:Effects of Hydroxyapatite Crystallites Orientation and Microstructure"

Tomohiro Nakatsuji, Kazufumi Yamamoto, Daisuke Suga, Takahiko Yanagitani, Mami Matsukawa, Kaoru Yamazaki, and Yukihiro Matsuyama

Jpn. J. Appl. Phys. Peer Review Yes 50(07HF18) p.1 - 62011/07-

Detail

Publish Classification:Research paper (scientific journal)

T. Yoshida et al., "Observation of induced longitudinal and shear acoustic phonons by Brillouin scattering"

T. Yoshida, T. Yanagitani, and M. Matsukawa,

IEEE Trans. Ultrason., Ferroelectr., Freq. Contr., Peer Review Yes 58(6) p.1255 - 12602011/06-

Detail

Publish Classification:Research paper (scientific journal)

T. Yanagitani et al., "c-axis zig-zag ZnO film ultrasonic transducers for designing longitudinal and shear wave resonant frequencies and modes'

T. Yanagitani, N Morisato, S. Takayanagi, M. Matsukawa, and Y. Watanabe,

IEEE Trans. Ultrason., Ferroelectr., Freq. Contr. Peer Review Yes 58(5) p.1062 - 10682011/05-

Detail

Publish Classification:Research paper (scientific journal)

T. Yanagitani and M. Kiuchi, "Texture modification of wurtzite piezoelectric films by ion beam irradiation"

T. Yanagitani and M. Kiuchi

Surf. Coat. Technol., Peer Review Yes 206p.816 - 8192011/04-

Detail

Publish Classification:Research paper (scientific journal)

T. Yanagitani, et. al., "A method for measuring in-plane unidirectional electrical properties in a wide band-gap semiconductor using a Brillouin scattering method"

T. Yanagitani, H. Sano, and M. Matsukawa

J. Appl. Phys. Peer Review Yes 108(024910) p.1 - 42010/07-

Detail

Publish Classification:Research paper (scientific journal)

T. Kawamoto, et. al., "Large-area growth of in-plane oriented (11-20) ZnO films by linear cathode magnetron sputtering"

T. Kawamoto, T. Yanagitani, M. Matsukawa, Y. Watanabe, Y. Mori, S. Sasaki, and M. Oba

Jpn. J. Appl. Phys. Peer Review Yes 49(07HD16) p.1 - 42010/07-

Detail

Publish Classification:Research paper (scientific journal)

A. Tanaka, et. al., "Propagation characteristics of shear horizontal surface acoustic waves in (11-20) ZnO film/silica glass substrate structures"

A. Tanaka, T. Yanagitani, M. Matsukawa, and Y. Watanabe

IEEE Trans. Ultrason., Ferroelectr., Freq. Contr. Peer Review Yes 55p.2709 - 2713 2008/12-

Detail

Publish Classification:Research paper (scientific journal)

Y. Yamato., et. al., "Distribution of hydroxyapatite crystallites orientation and longitudinal wave velocity in ring-shaped cortical bone of bovine femur"

Y. Yamato, M. Matsukawa, H. Mizukawa, T. Yanagitani, K. Yamazaki, and A. Nagano

IEEE Trans. Ultrason., Ferroelectr., Freq. Contr. Peer Review Yes 55(6) p.1298 - 13032008/06-

Detail

Publish Classification:Research paper (scientific journal)

T. Yanagitani, et. al.,"Characteristics of pure-shear mode BAW resonators consisting of (11-20) textured ZnO films"

T. Yanagitani, M. Kiuchi, M. Matsukawa, and Y. Watanabe

IEEE Trans. Ultrason., Ferroelectr., Freq. Contr. Peer Review Yes 54(8) p.1680 - 16862007/08-

Detail

Publish Classification:Research paper (scientific journal)

T. Yanagitani, and M. Kiuchi, "Control of in-plane and out-of-plane texture in shear mode piezoelectric ZnO films by ion-beam irradiation"

T. Yanagitani and M. Kiuchi

J. Appl. Phys. Peer Review Yes 102(4) p.044115-1 - 044115-72007/08-

Detail

Publish Classification:Research paper (scientific journal)

T. Yanagitani, et. al., "Shear-mode electromechanical coupling coefficient k15 and crystallites alignment of (11-20) textured ZnO films"

T. Yanagitani, M. Kiuchi, M. Matsukawa, and Y. Watanabe

J. Appl. Phys. Peer Review Yes 102(2) p.024110-1 - 024110-72007/07-

Detail

Publish Classification:Research paper (scientific journal)

Electromechanical coupling coefficient k15 of polycrystalline ZnO films with the c-axes lie in the substrate plane

T. Yanagitani, N. Mishima, M. Matsukawa, and Y. Watanabe

IEEE Trans. Ultrason., Ferroelectr., Freq. Contr. Peer Review Yes 54(4) p.701 - 7042007/04-

Detail

Publish Classification:Research paper (scientific journal)

Conversion characteristics of the shear wave transducer made of unidirectionally aligned ZnO film in plane

T. Nohara, T. Yanagitani, M. Matsukawa, and Y. Watanabe

Jpn. J. Appl. Phys. Peer Review Yes 45(5A) p.4201 - 42032006/05-

Detail

Publish Classification:Research paper (scientific journal)

Effect of sputtering geometry on the (11-20) textured ZnO piezofilm

Y. Miyamoto, T. Yanagitan, M. Matsukawa, and Y. Watanabe

Acoust. Sci. & Tech. Peer Review Yes 27(1) p.53 - 552006/01-

Detail

Publish Classification:Research paper (scientific journal)

Characteristics of (10-10) and (11-20) textured ZnO piezofilms for a shear mode resonator in the VHF-UHF frequency ranges

T. Yanagitani, T. Nohara, M. Matsukawa, Y. Watanabe, and T. Otani

IEEE Trans. Ultrason., Ferroelectr., Freq. Contr. Peer Review Yes 52(11) p.2140 - 21452005/11-

Detail

Publish Classification:Research paper (scientific journal)

Formation of uniaxially (11-20) textured ZnO film on glass substrates

T. Yanagitani, M. Matsukawa, Y. Watanabe, and T. Otani

J. Cryst. Growth Peer Review Yes 276p.424 - 4302005/04-

Detail

Publish Classification:Research paper (scientific journal)

Characterizations of (11-20) textured ZnO films fabricated by RF magnetron sputtering

T. Yanagitani, S. Tomohiro, T. Nohara, M. Matsukawa, Y. Watanabe, and T. Otani

Jpn. J. Appl. Phys. Peer Review Yes 43(5B) p.3004 - 30072004/03-

Detail

Publish Classification:Research paper (scientific journal)

Y. Yaoi, et. al., "Anisotropy of longitudinal wave velocity and hydroxyapatite orientation in bovine cortical bone"

Y. Yaoi, K. Yamamoto, T. Nakatsuji, T. Yanagitani, M. Matsukawa, K. Yamazaki, and A. Nagano

Jpn. J. Appl. Phys. Peer Review Yes 48p.07GK06-1 - 07GK06-42009/07-

Detail

Publish Classification:Research paper (scientific journal)

Distribution of longitudinal wave velocity and hydroxyapatite crystallite orientation in bovine cortical bone

Y. Yaoi, K. Yamamoto, Y. Yamato, T. Yanagitani, M. Matsukawa, K. Yamazaki, and A. Nagano,

Acoust. Sci. & Tech. Peer Review Yes 30p.306 - 3092009/04-

Detail

Publish Classification:Research paper (scientific journal)

Ultrasonic wave properties in the bone axis direction of bovine cortical bone

K. Yamamoto, Y. Yaoi, Y. Yamato, H. Mizukawa, T. Yanagitani, M. Matsukawa, K. Yamazaki, and A. Nagano

Jpn. J. Appl. Phys. Peer Review Yes 47p.4096 - 41002008/05-

Detail

Publish Classification:Research paper (scientific journal)

Y. Yamato., et. al., "Correlation between hydroxyapatite crystallite orientation and ultrasonic wave velocities in bovine cortical bone"

Y. Yamato, M. Matsukawa, T. Yanagitani, K. Yamazaki, H. Mizukawa, and A. Nagano

Calcif Tissue Int. Peer Review Yes 82(2) p.162 - 1692008/02-

Detail

Publish Classification:Research paper (scientific journal)

T. Yanagitani and M. Kiuchi, "Highly oriented ZnO thin films deposited by grazing ion-beam sputtering: application to acoustic shear wave excitation in the GHz range"

T. Yanagitani and M. Kiuchi

Jpn. J. Appl. Phys. Peer Review Yes 46(47) p.L1167 - L11692007/11-

Detail

Publish Classification:Research paper (scientific journal)

Effects of sputtering gas conditions on formation of (11-20) textured ZnO films

T. Kawamoto, T. Yanagitani, M. Matsukawa, and Y. Watanabe

Jpn. J. Appl. Phys. Peer Review Yes 46(7B) p.4660 - 46642007/07-

Detail

Publish Classification:Research paper (scientific journal)

Observation of induced shear acoustic phonons by Brillouin scattering

S. Murata, T. Kawamoto, M. Matsukawa, T. Yanagitani, and N. Ohtori

Jpn. J. Appl. Phys. Peer Review Yes 46(7B) p.4626 - 46282007/07-

Detail

Publish Classification:Research paper (scientific journal)

Multiple shear wave roundtrips liquid sensor by c-axis parallel oriented ZnO film/silica glass pipe structure

S. Hiyama, T. Yanagitani, S. Takayanagi, Y. Kato, M. Matsukawa

Proc. IEEE Ultrason. Symp. p.765 - 7682015/03-

Detail

Publish Classification:Research paper (international conference proceedings)

Effect of Sc concentration on shear wave velocities in ScAlN films measured by micro-Brillouin scattering technique

H. Ichihashi, T. Yanagitani, S. Takayanagi1, M. Matsukawa

Proc. IEEE Ultrason. Symp. p.2521 - 25242015/03-

Detail

Publish Classification:Research paper (international conference proceedings)

High electromechanical coupling in PZT epitaxial thick film resonators at 550 degC

T. Yanagitani, K. Katada, M. Suzuki, K. Wasa

Proc. IEEE Freq. Contr. Symp. p.121 - 1232014/05-

Detail

Publish Classification:Research paper (international conference proceedings)

Second harmonic mode polarization inverted resonator consisting of PbTiO3 thin film

K. Katada, T. Yanagitani, M. Suzuki, K. Wasa

Proc. IEEE Freq. Contr. Symp. p.119 - 1202014/05-

Detail

Publish Classification:Research paper (international conference proceedings)

High Tc /High Coupling Perovskite Thin Films

K. Wasa, T. Matsushima, H. Adachi, T. Matsunaga, T. Yanagitani, T. Yamamoto

Proc. IEEE ISAF/IWATMD/PFM p.1 - 42014/05-

Detail

Publish Classification:Research paper (international conference proceedings)

Fast hypersonic velocity measurement by Brillouin scattering from induced phonons

Takeshi Sugimoto, Takahiko Yanagitani, Shinji Takayanagi and Mami Matsukawa

Proc. IEEE Ultrason. Symp. 1p.2187 - 21902013/04-

Detail

Publish Classification:Research paper (international conference proceedings)

M. Suzuki, and T. Yanagitani, c-axis parallel oriented AlN film resonator fabricated by ion-beam assisted RF magnetron sputtering,”

M. Suzuki, and T. Yanagitani

Proc. IEEE Ultrason. Symp. 1p.1230 - 12332012/05-

Detail

Publish Classification:Research paper (international conference proceedings)

Quantitative analysis of the effect of energetic particle bombardment during deposition on (11-20) ZnO piezoelectric films

S. Takayanagi, T. Yanagitani, M. Matsukawa, Y. Watanabe,

Proc. IEEE Ultrason. Symp. 1p.2317 - 23202012/05-

Detail

Publish Classification:Research paper (international conference proceedings)

Brillouin scattering from induced phonons excited by the ZnO piezoelectric thin film with a coaxial resonator,

T. Sugimoto, H. Sano, T. Yanagitani, S. Takayanagi, M. Matsukawa,

Proc. IEEE Ultrason. Symp. 1p.1099 - 11022012/05-

Detail

Publish Classification:Research paper (international conference proceedings)

c-axis parallel oriented ZnO film SH-SAW sensor for electrical conductivity measurement in liquid

Y. Nakahigashi, T. Yanagitani,M. Matsukawa,Y. Watanabe

Proc. IEEE Ultrason. Symp. 1p.810 - 8132012/05-

Detail

Publish Classification:Research paper (international conference proceedings)

M. Suzuki, and T. Yanagitani, Polarizaion-inverted multilayered pure shear mode AlN film resonator

M. Suzuki, and T. Yanagitani

Proc. IEEE Ultrason. Symp. 1p.312 - 3152012/05-

Detail

Publish Classification:Research paper (international conference proceedings)

Highest wave velocity direction in the bovine cortical bone: observation of a small tilt relative to the bone axis

T. Nakatsuji, K. Yamamoto, T. Yanagitani, M. Matsukawa, K. Yamazaki

Proc. IEEE Ultrason. Symp. 2011/04-

Detail

Publish Classification:Research paper (international conference proceedings)

A simple technique for obtaining (11-20) or (10-10) textured ZnO films by RF bias sputtering

S. Takayanagi, T. Yanagitani, M. Matsukawa, Y. Watanabe

Proc. IEEE Ultrason. Symp. p.1060 - 10632011/04-

Detail

Publish Classification:Research paper (international conference proceedings)

Deposition techniques of c-axis-tilted ScAlN films by conventional RF magnetron sputtering

K. Arakawa, T. Yanagitani, K. Kano, A. Teshigahara, M. Akiyama

Proc. IEEE Ultrason. Symp. p.1050 - 10532011/04-

Detail

Publish Classification:Research paper (international conference proceedings)

Influence of shadowing effect on shear mode acoustic properties in the c-axis tilted AlN films

M Suzuki, and T. Yanagitani

Proc. IEEE Ultrason. Symp. p.1478 - 14812011/04-

Detail

Publish Classification:Research paper (international conference proceedings)

Giant shear mode electromechanical coupling coefficient k15 in c-axis tilted ScAlN films

T. Yanagitani, K. Arakawa, M. Suzuki, K. Kano, T. Akihiko, A. Morito,

Proc. IEEE Ultrason. Symp. p.2095 - 20982011/04-

Detail

Publish Classification:Research paper (international conference proceedings)

Effects of HAp alignment and microstructure on the anisotropy of longitudinal wave velocity in bovine cortical bone

K. Yamamoto, T. Nakatsuji, Y. Yamato, T. Yanagitani, K. Yamazaki, M. Matsukawa, Y. Matsuyama

Proc. IEEE Ultrason. Symp. 2011/04-

Detail

Publish Classification:Research paper (international conference proceedings)

Multilayered shear wave resonator consisting of c-axis tilted ZnO films

N. Morisato, S. Takayanagi, T. Yanagitani, M. Matsukawa and Y. Watanabe

Proc. IEEE Ultrason. Symp. 2009 p.2162 - 21652010/03-

Detail

Publish Classification:Research paper (international conference proceedings)

Measurement of electric properties in a ZnO single crystal via electromechanical coupling using Brillouin scattering method

T. Yanagitani, H. Sano, and M. Matsukawa

Proc. IEEE Ultrason. Symp. p.1074 - 10772010/03-

Detail

Publish Classification:Research paper (international conference proceedings)

Anisotropy of longitudinal wave velocity in spherically shaped bovine cortical bone

K. Yamamoto, T. Nakatsuji, M. Indo, T. Yanagitani, M. Matsukawa, K. Yamazaki

IFMBE Proceedings 27p.102 - 1052010/01-

Detail

Publish Classification:Research paper (international conference proceedings)

超音波による骨質の評価

山崎薫, 大和雄, 山本和史, 長野昭, 松川真美, 矢追佑一郎, 柳谷隆彦

オポローシス・ジャパン 16p.388 - 3922008/04-

Detail

Publish Classification:Research paper (international conference proceedings)

Pure-shear mode BAW resonator consisting of (10-10) and (11-20) textured AlN films

T. Yanagitani and Masato Kiuchi

Proc. IEEE Ultrason. Symp. 2008 p.90 - 932008/04-

Detail

Publish Classification:Research paper (international conference proceedings)

Electromechanical coupling coefficient of semiconducting hexagonal crystal measured by Brillouin scattering

T. Yanagitani , Y. Yoshida,and M. Matsukawa

Proc. IEEE Ultrason. Symp. 2008 p.1487 - 14902008/04-

Detail

Publish Classification:Research paper (international conference proceedings)

Pure-shear mode BAW resonators consisting of (11-20) textured ZnO films

T. Yanagitani, M. Kiuch, M. Matsukawa and Y. Watanabe

Acoustics 08 Paris p.4987 - 49922008/04-

Detail

Publish Classification:Research paper (international conference proceedings)

Observation of induced shear acoustic phonons by Brillouin scattering

T. Yoshida, S. Murata, T. Yanagitani and M. Matsukawa

Acoustics 08 Paris p.4605 - 46092008/04-

Detail

Publish Classification:Research paper (international conference proceedings)

Propagation characteristics of SH-SAW in (11 0) ZnO layer/silica glass substrate structures

A. Tanaka, T. Yanagitani, M. Matsukawa, Y. Watanabe

Proc. IEEE Ultrason. Symp. 2007 p.280 - 2832007/04-

Detail

Publish Classification:Research paper (international conference proceedings)

Thin film stack transducer for simultaneous generation of longitudinal and shear waves at same frequency

T. Yanagitani, T. Matsuo, M. Matsukawa, Y. Watanabe

Proc. IEEE Ultrason. Symp. 2007 p.1874 - 18772007/04-

Detail

Publish Classification:Research paper (international conference proceedings)

Ion beam sputter-deposited ZnO thin film for broadband shear wave excitation in the GHz range

T. Yanagitani, M. Kiuchi

Proc. IEEE Ultrason. Symp. 2007 p.1413 - 14162007/04-

Detail

Publish Classification:Research paper (international conference proceedings)

Highly oriented c-axis 23° tilted ZnO films with high quasi-shear mode electromechanical coupling coefficients

T. Matsuo, T. Yanagitani, M. Matsukawa, Y. Watanabe

Proc. IEEE Ultrason. Symp. 2007 p.1229 - 12322007/04-

Detail

Publish Classification:Research paper (international conference proceedings)

Study on formation mechanism of (11-20) textured ZnO films

K. Kawamoto, M. Matsukawa, Y. Watanabe, and T. Yanagitani

Proc. IEEE Ultrason. Symp. 2006 p.1529 - 15322006/04-

Detail

Publish Classification:Research paper (international conference proceedings)

Electromechanical coupling coefficient k15 and crystallites alignment of (11-20) textured ZnO film

T. Yanagitani, M. Kiuchi, M. Matsukawa, and Y. Watanabe

Proc. IEEE Ultrason. Symp. 2006 p.1463 - 14662006/04-

Detail

Publish Classification:Research paper (international conference proceedings)

Temperature characteristics of pure shear mode FBARs consisting of (11-20) textured ZnO films

T. Yanagitani, M. Kiuchi, M. Matsukawa, and Y. Watanabe

Proc. IEEE Ultrason. Symp. 2006 p.1459 - 14622006/04-

Detail

Publish Classification:Research paper (international conference proceedings)

Elastic anisotropy and crystallites orientation in bovine cortical bone

Y. Yamato, H. Mizukawa, T. Yanagitani, M. Matsukawa, K. Yamazaki, and A. Nagano

Proc. IEEE Ultrason. Symp. 2006 p.2120 - 21232006/04-

Detail

Publish Classification:Research paper (international conference proceedings)

Electromechanical coupling coefficient k15 of (11-20) textured ZnO films

T. Yanagitani, N. Mishima, M. Matsukawa, and Y. Watanabe

Proc. IEEE Ultrason. Symp. 2005 p.1824 - 18272005/04-

Detail

Publish Classification:Research paper (international conference proceedings)

Higher-order shear mode FBAR using polarization-inverted layers of (11-20) textured ZnO films

Y. Miyamoto, T. Yanagitani, M. Matsukawa, and Y. Watanabe

Proc. IEEE Ultrason. Symp. 2005 p.1828 - 18312005/04-

Detail

Publish Classification:Research paper (international conference proceedings)

Shear wave transducer using (11-20) textured ZnO film

T. Yanagitani, T. Nohara, M. Matsukawa, Y. Watanabe, and T. Otani

Proc. IEEE Ultrason. Symp. 2004., p.906 - 9092004/04-

Detail

Publish Classification:Research paper (international conference proceedings)

Nondestructive evaluation of thin ZnO shear transducer by Brillouin scattering

K. Shintani, T. Yanagitani, M. Matsukawa, and T. Otani

Proc. IEEE Ultrason. Symp. 2004 p.1864 - 18672004/04-

Detail

Publish Classification:Research paper (international conference proceedings)

1P5-4 Ultrasonically induced electric potentials in the cortical bone

Matsukawa Sayaka;Mori Shunki;Fontanel Elodie;Mano Isao;Mizuno Katsunori;Yanagitani Takahiko;Takayanagi Shinji;Matsukawa Mami

Proceedings of Symposium on Ultrasonic Electronics 36p."1P5 - 4-1"-"1P5-4-2"2015/11-2015/11

CiNii

Detail

ISSN:13488236

2P1-7 Shear mode electromechanical coupling coefficient of c-axis parallel oriented ZnO films by sputtering with H2O

Takata Chihiro;Takayanagi Shinji;Yanagitani Takahiko;Matsukawa Mami

Proceedings of Symposium on Ultrasonic Electronics 36p."2P1 - 7-1"-"2P1-7-2"2015/11-2015/11

CiNii

Detail

ISSN:13488236

3J2-2 Polarity inverted Al-polar ScAlN/O-polar ZnO multilayers for high conversion efficiency transducer in the GHz range

Mori Takeshi;Suzuki Masashi;Yanagitani Takahiko

Proceedings of Symposium on Ultrasonic Electronics 36p."3J2 - 2-1"-"3J2-2-2"2015/11-2015/11

CiNii

Detail

ISSN:13488236

3J3-2 Growth of c-axis parallel oriented ScAlN films by ion-beam assisted sputtering and their application in pure shear mode resonators

Oka Mineki;Takayanagi Shinji;Yanagitani Takahiko;Matsukawa Mami

Proceedings of Symposium on Ultrasonic Electronics 36p."3J3 - 2-1"-"3J3-2-2"2015/11-2015/11

CiNii

Detail

ISSN:13488236

3P3-2 Effect of Sc concentration on quasi-shear mode electromechanical coupling k'_<15> in c-axis tilted ScAlN films

Suzuki Masashi;Yanagitani Takahiko

Proceedings of Symposium on Ultrasonic Electronics 36p."3P3 - 2-1"-"3P3-2-2"2015/11-2015/11

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ISSN:13488236

Fast wave velocity measurement by Brillouin scattering using coherent induced phonon from ScAlN piezoelectric thin film

Kawabe, Masahiko; Ichihashi, Hayato; Takayanagi, Shinji; Matsukawa, Mami; Yanagitani, Takahiko; Suzuki, Masashi

2015 IEEE International Ultrasonics Symposium, IUS 2015 2015/11-2015/11

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Outline:© 2015 IEEE.Brillouin scattering is a nondestructive and noncontact technique to measure local longitudinal and shear acoustic velocities in the GHz range. However, the measurements of weak scattering from thermal phonons result in the lower measurement accuracy and longer measurement time. To overcome this problem, a technique with artificially induced acoustic phonons was developed using a ScAlN film. We observed Brillouin scattering by induced longitudinal coherent phonons from ScAlN film deposited on the side surface of a silica bulk specimen. The intensity of induced acoustic phonons was experimentally studied.

Shear mode properties of c-axis parallel oriented ScxAl1-xN films grown by RF bias sputtering

Takayanagi, Shinji; Matsukawa, Mami; Yanagitani, Takahiko

2015 IEEE International Ultrasonics Symposium, IUS 2015 2015/11-2015/11

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Outline:© 2015 IEEE.Because the increase of piezoelectricity was found in Sc heavily doped AlN films, they have been well studied. Many researchers investigate the properties of the longitudinal mode bulk acoustic wave with c-axis normally oriented ScAlN films. However, there are few reports on the shear mode properties because of difficulties in growth of c-axis parallel oriented ScAlN films which can excite shear mode bulk acoustic wave. In this study, we demonstrated the film growth of c-axis parallel oriented ScAlN using RF substrate bias RF magnetron sputtering method. As a result of X-ray diffraction analyses, we obtained c-axis parallel oriented AlN, Sc0.05Al0.95N and Sc0.13Al0.87N films. Then, High overtone bulk acoustic wave resonators were fabricated with these films. They excited shear mode bulk acoustic wave, but shear mode conversion losses were large (more than 20 dB). It is necessary to obtain highly-crystallized ScAlN films.

Acoustic-Wave Velocities and Refractive Indices in an m-Plane GaN Single-Crystal Plate and c-Axis-Oriented ScAlN Films Measured by Brillouin Scattering Techniques

Ichihashi, Hayato; Yanagitani, Takahiko; Suzuki, Masashi; Takayanagi, Shinji; Kawabe, Masahiko; Tomita, Shota; Matsukawa, Mami

IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 63(5) p.117 - 1252016/05-2016/05

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ISSN:08853010

Outline:© 2016 IEEE.We have experimentally investigated wave velocities and refractive indices in bulk and film samples [a GaN single-crystal plate and c-axis-oriented ScxAl(1-x)N (x= 0.00-0.63) films] by Brillouin scattering (BRS). All of the piezoelectrically unstiffened elastic constants and the ordinary refractive index of the GaN single-crystal plate were determined from the reflection-induced θA(RIθA) scattering geometry and the combination of 90R and 180° scattering geometries. The uncertainties of the measured wave velocities were approximately 0.17% (RIθA) and 2.5% (combination technique). In addition, the longitudinal-wave velocities of ScxAl(1-x)N films propagating in the normal direction were obtained by the combination technique. The maximum uncertainty was approximately 3.3%. The shear-wave velocities and refractive indices of ScxAl(1-x)N films were also investigated by the 90R scattering geometry using velocities measured by high-overtone bulk acoustic resonators. The softening trends of the elasticity were obtained from the measured longitudinal- and shear-wave velocities, although there were large uncertainties in the Brillouin measurement system owing to thermal instability.

Method for measuring polarity-inverted layered structure in dielectric thin films using scanning nonlinear dielectric microscopy

Odagawa, Hiroyuki; Terada, Koshiro; Nishikawa, Hiroaki; Yanagitani, Takahiko; Cho, Yasuo

Ferroelectrics 498(1) p.47 - 512016/08-2016/08

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ISSN:00150193

Outline:© 2016, © Taylor & Francis Group, LLC.A method for obtaining a depth profile of polarity inverted structure in a layered ferroelectric and/or piezoelectric thin film is proposed. It is performed by surface measurement non-destructively using scanning nonlinear dielectric microscopy. We describe estimation principle for the depth profile with some calculation results of measurement signal, which is related to tip radius of the measurement probe and depth of the inverted layer. Also, experimental results in zinc oxide films which have layered polarity-inverted structure fabricated by radio frequency magnetron sputtering and the estimation of the polarity state on the films are shown.

Effects of energetic negative ions generated from sputtering targets on ScAlN film growth

Takayanagi, Shinji; Matsukawa, Mami; Yanagitani, Takahiko

IEEE International Ultrasonics Symposium, IUS 2016-November2016/11-2016/11

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ISSN:19485719

Outline:© 2016 IEEE.ScAlN films is attractive for high-frequency piezoelectric devices. In previous study, we demonstrated Sc ingot sputtering in which Sc ingots were set on an Al metal target. Oxidization of Sc ingots was seriously problem because the c-axis orientation of ScAlN films was degraded. In this study, we investigated the energy distributions of O- negative ion which enter the substrate during the deposition. The amount of the O- ion flux decreased with duration, but it remained large. Therefore, the crystalline orientation and the longitudinal mode conversion loss of ScAlN film were inferior to those using a ScAl alloy target. The suppression of the O- generation is required.

Rapid and simultaneous measurement of longitudinal and shear wave velocities by Brillouin scattering from artificially induced phonons

Kawabe, Masahiko; Shibagaki, Yoshiaki; Matsukawa, Mami; Yanagitani, Takahiko; Suzuki, Masashi; Takayanagi, Shinji

IEEE International Ultrasonics Symposium, IUS 2016-November2016/11-2016/11

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ISSN:19485719

Outline:© 2016 IEEE.For more accurate and rapid measurements of Brillouin light scattering, a technique with artificially induced acoustic phonons was proposed using a ScAlN film. The ScAlN film has a giant electromechanical coupling coefficient and can radiate coherent phonons in the sub GHz and GHz range. Making use of the induced phonons, we observed Brillouin scattering in the silica bulk sample. For efficient radiation of phonons, the ScAlN film was deposited on the side surface of the sample and reflection induced Θ angle geometry was used for Brillouin scattering measurements. The high intensity of Brillouin scattering from the induced acoustic phonons was experimentally studied.

Effect of anisotropy on stress-induced electrical potentials in bovine bone using ultrasound irradiation

Matsukawa, S.; Makino, T.; Mori, S.; Koyama, D.; Takayanagi, S.; Mizuno, K.; Yanagitani, T.; Matsukawa, M.

Applied Physics Letters 110(14) 2017/04-2017/04

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ISSN:00036951

Outline:© 2017 Author(s). The bone fracture healing mechanism of the low-intensity pulsed ultrasound technique is not yet clearly understood. In our previous study, the electrical potentials induced in bone were successfully measured by focusing on piezoelectricity in the MHz range. Bone is composed of collagen and hydroxyapatite and has strong anisotropy. The purpose of this study is to investigate the effects of bone anisotropy on the electrical potentials induced by ultrasound irradiation. For this study, ultrasound bone transducers were fabricated using cortical bovine bone plates as piezoelectric devices. An ultrasound of 7.4 kPa peak-peak (i.e., the peak-to-peak pressure value) was used to irradiate the side surface of each bone plate. Electrical potentials induced in the bone plate were then measured by varying the wave propagation direction in the plate. The peak-to-peak values of these ultrasonically induced electrical potentials were found to vary with changes in the ultrasound propagation direction in the bone sample. The potential was maximized at an inclination of approximately 45° to the bone axis but was minimized around the three orthogonal directions. These maxima and minima ranged from 28 to 33 μV peak-peak and from 5 to 12 μV peak-peak , respectively. Additionally, our ultrasound results indicated a change in polarity due to bone anisotropy in the MHz range.

Evaluation of the acoustoelectric effect in the thickness direction of c -plane ZnO single crystals by Brillouin scattering

Tomita, Shota; Yanagitani, Takahiko; Takayanagi, Shinji; Ichihashi, Hayato; Shibagaki, Yoshiaki; Hayashi, Hiromichi; Matsukawa, Mami

Journal of Applied Physics 121(23) 2017/06-2017/06

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ISSN:00218979

Outline:© 2017 Author(s). Longitudinal wave velocity dispersion in ZnO single crystals, owing to the acoustoelectric effect, has been investigated by Brillouin scattering. The resistivity dependence of the longitudinal wave velocity in a c-plane ZnO single crystal was theoretically estimated and experimentally investigated. Velocity dispersion owing to the acoustoelectric effect was observed in the range 0.007-10 Ωm. The observed velocity dispersion shows a similar tendency to the theoretical estimation and gives the piezoelectric stiffened and unstiffened wave velocities. However, the measured dispersion curve shows a characteristic shift from the theoretical curve. One possible reason is the carrier mobility in the sample, which could be lower than the reported value. The measurement data gave the piezoelectric stiffened and unstiffened longitudinal wave velocities, from which the electromechanical coupling coefficient k 33 was determined. The value of k 33 is in good agreement with reported values. This method is promising for noncontact evaluation of electromechanical coupling. In particular, it could be for evaluation of the unknown piezoelectricity in the thickness direction of semiconductive materials and film resonators.

Thick ScAlN film for high efficient ultrasonic transducer in low frequency of 81 MHz

Sano, Ko Hei; Karasawa, Rei; Yanagitani, Takahiko; Yanagitani, Takahiko

TRANSDUCERS 2017 - 19th International Conference on Solid-State Sensors, Actuators and Microsystems p.862 - 8652017/07-2017/07

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Outline:© 2017 IEEE. Large piezoelectricity in 43% Sc doped ScAlN thin film has been recently reported. The thickness extensional mode resonant frequency, where ultrasonic generation efficiency become large, is inversely proportional to the thickness of films. Bulk ScAlN thick plates are attractive for the low frequency and high power ultrasonic applications such as actuators and medical ultrasonics because ScAlN possess lower mechanical and dielectric losses compared with well-used PZT. The thick ScAlN films, however, has not been reported. The electromechanical coupling coefficient k t 2 was determined to be 19% using the thickness extensional mode at 81 MHz. This frequency is extremely low compared to well-reported ScAlN thin films in the GHz ranges.

Broadband frequency viscositymeasurement using low TCF shear mode resonators consisting of C-axis tilted scaln thin film on thick at-cut quartz plate

Yamakawa, Y.; Sano, K.; Karasawa, R.; Yanagitani, T.; Yanagitani, T.

TRANSDUCERS 2017 - 19th International Conference on Solid-State Sensors, Actuators and Microsystems p.2135 - 21382017/07-2017/07

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Outline:© 2017 IEEE. In order to study relaxation characteristics of acoustic velocity and viscoelasticity of the liquid, a wide frequency sweep in the range of MHz to GHz is desired. Thickness shear acoustic mode (TSM) viscosity sensors such as QCM or FBAR can only operate at the MHz range or the GHz range, respectively. In this study, therefore, we report a new type HBAR (High-overtone Bulk Acoustic Resonator) sensor which makes it possible to operate in a wide frequency range. The HBAR consists of the c-axis tilted ScAlN film grown on a zero TCF AT-cut quartz crystal plate. Frequency shifts were measured for various concentration of glycerine solutions. As a result, the tendency of resonant frequency decreasing caused by liquid viscosity increasing is observed in both theoretical and experimental data.

Quantitative thickness measurement of polarity-inverted piezoelectric thin-film layer by scanning nonlinear dielectric microscopy

Odagawa, Hiroyuki; Terada, Koshiro; Tanaka, Yohei; Nishikawa, Hiroaki; Yanagitani, Takahiko; Cho, Yasuo

Japanese Journal of Applied Physics 56(10) 2017/10-2017/10

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Detail

ISSN:00214922

Outline:© 2017 The Japan Society of Applied Physics. A quantitative measurement method for a polarity-inverted layer in ferroelectric or piezoelectric thin film is proposed. It is performed nondestructively by scanning nonlinear dielectric microscopy (SNDM). In SNDM, linear and nonlinear dielectric constants are measured using a probe that converts the variation of capacitance related to these constants into the variation of electrical oscillation frequency. In this paper, we describe a principle for determining the layer thickness and some calculation results of the output signal, which are related to the radius of the probe tip and the thickness of the inverted layer. Moreover, we derive an equation that represents the relationship between the output signal and the oscillation frequency of the probe and explain how to determine the thickness from the measured frequency. Experimental results in Sc-doped AlN piezoelectric thin films that have a polarity-inverted layer with a thickness of 1.5 μm fabricated by radio frequency magnetron sputtering showed a fairly good value of 1.38 μm for the thickness of the polarity-inverted layer.

A new type wide-frequency-range shear viscosity sensor using c-axis tilted ScAlN thin film on temperature stable AT-cut quartz thick plate

Yamakawa, Yui; Sano, Kohei; Karasawa, Rei; Yanagitani, Takahiko; Yanagitani, Takahiko

IEEE International Ultrasonics Symposium, IUS 2017/10-2017/10

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Detail

ISSN:19485719

Outline:© 2017 IEEE. In order to study relaxation characteristics of viscoelasticity of the liquid, a wide frequency sweep in the range of MHz to GHz is desired. We, therefore, report a new type HBAR (High-overtone Bulk Acoustic Resonator: shear mode ScAlN film on AT-cut quartz plate) sensor which makes it possible to operate in a wide frequency range as shown in Fig. 1. When a thickness shear acoustic mode (TSM) resonator is in contact with a liquid sample, the shear wave penetrates into the liquid by the depth of δ (called penetration depth [1] ). Thus, the liquid viscosity can be determined from the amount of the resonant frequency shift due to a δ thick mass loading layer mounted on the resonator. We choose AT-cut quartz as the substrate whose TCF is zero at room temperature to suppress frequency shifts due to the temperature change. TCF of the whole resonator stack greatly decreases considering the mass ratio between the thin piezoelectric film and the much thicker substrate. In this study, frequency shifts were measured for various concentration of glycerine solutions in order to demonstrate usefulness of the HBAR. [1] T. Nakamoto and T. Moriizumi, Jpn. J. Appl. Phys., 29 963 (1990).

The frequency switchable multi-layered BST/BaTiO3epitaxial film resonator

Shimidzu, Takahiro; Yanagitani, Takahiko; Yanagitani, Takahiko; Wasa, Kiyotaka

IEEE International Ultrasonics Symposium, IUS 2017/10-2017/10

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ISSN:19485719

Outline:© 2017 IEEE. The frequency switchable filters are suitable for selecting the vacant frequency bands. Usual polarity unidirectional single-layered resonators excite 1 st mode whereas polarity inverted two-layered resonators excite 2 nd mode. We previous reported the frequency switchable two-layered PZT/PbTiO 3 epitaxial film resonators[1]. However, PbTiO 3 films grown on PZT/PbTiO 3 films are difficult to obtain since Curie temperature and deposition temperature in PbTiO 3 are higher than those of PZT. (Ba x , Sr 1-x )TiO 3 (BST) films exhibit electrostrictive effect in paraelectric phase. In ferroelectric BaTiO 3 , on the other hand, polarity inversion is impossible to be obtained without the application of higher than coercive electric field to films. Therefore, in this study, we considered that polarity inverted structure is easily obtained by application of less than coercive electric field of BaTiO 3 to two-layered BaTiO 3 /BST epitaxial films. [1] T. Mori, et al., Proc. IUS 2016.

High electromechanical coefficient kt2=19% thick ScAlN piezoelectric films for ultrasonic transducer in low frequency of 80 MHz

Sano, Ko Hei; Karasawa, Rei; Yanagitani, Takahiko; Yanagitani, Takahiko; Yanagitani, Takahiko

IEEE International Ultrasonics Symposium, IUS 2017/10-2017/10

DOIScopus

Detail

ISSN:19485719

Outline:© 2017 IEEE. Ultrasonic transducers in the frequency ranges of 20-100 MHz is not well-developed because of less applications or less suitable piezoelectric materials. PVDF are usually used for ultrasonic transducers in the 10-50 MHz ranges. However, their electromechanical coupling coefficient k t 2 of 4% is not enough for the practical uses. In order to excite ultrasonic in the 20-100 MHz, 125 μm-25 μm thick piezoelectric film is required. It is difficult to grow such a thick piezoelectric film without a crack caused by the internal stress during the PVD deposition technique. We achieved stress free film growth by employing the unique hot cathode sputtering technique without heating substrate. We demonstrated high efficient 81 MHz (k t 2 =18.5%) and 43 MHz (k t 2 =11.9%) ultrasonic generation by using the 43 μm and 90 μm extremely thick ScAlN(Sc:39%) films, respectively.

Effects of negative oxygen ions generated during Sc ingot sputtering on electromechanical coupling of ScAlN film

Takayanagi, Sliinji; Yanagitani, Takahiko

IEEE International Ultrasonics Symposium, IUS 2017/10-2017/10

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ISSN:19485719

Outline:© 2017 IEEE. ScAlN films are well-researched for GHz acoustic wave devices. Large-area growth techniques of ScAlN films are necessary for the practical application. A single sputtering source with a ScAl alloy metal target is suitable for the film growth from the point of view of the composition stability. However, it is difficult to alloy Al with Sc in the large-size target. Therefore, a mosaic target of Sc and Al metals is reasonable for the large-area growth. In previous study, we demonstrated Sc ingot sputtering deposition [1] in which Sc ingots were set on an Al metal target as similar conditions with the mosaic target. Oxidization of Sc ingots was seriously problem in this method because the c-axis orientation of ScAlN films was degraded by bombardment with O-negative ions generated from the target. In this study, we investigated the effects of the negative ion bombardment on the crystalline orientations and piezoelectric properties.

Film growth of c-axis parallel oriented ZnO on entire surface of silica glass pipe for SH-SAW pipe sensor

Takamura, Yuta; Takayanagi, Shinji; Matsukawa, Mami; Ishida, Chizu; Yanagitani, Takahiko

IEEE International Ultrasonics Symposium, IUS 2017/10-2017/10

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ISSN:19485719

Outline:© 2017 IEEE. SH-SAW is suitable for liquid sensors to measure conductivity and viscosity because it can propagate without the energy leakage into liquid. We have fabricated a SH-SAW sensor consisting of a c-axis parallel (11-20) oriented ZnO film on a silica glass plate [1]. On the other hand, the long-distance propagation is necessary in order to detect the small changes of the velocity and amplitude. One way to increase propagation distance is wave multiple roundtrips around the sensor. In previous study, the c-axis parallel oriented ZnO film was grown on a part of the glass pipe surface and the SH-BAW roundtrips were demonstrated [2] . However, the SH-SAW roundtrips were not observed because the ZnO film was not grown on the entire surface of the pipe. In this study, we demonstrated the entirepipe-surface deposition of c-axis parallel oriented ZnO film to obtain SH-SAW pipe sensor.

The frequency switchable multi-layered BST/BaTiO3epitaxial film resonator

Shimidzu, Takahiro; Yanagitani, Takahiko; Wasa, Kiyotaka

IEEE International Ultrasonics Symposium, IUS 2017/10-2017/10

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Detail

ISSN:19485719

Outline:© 2017 IEEE. Film bulk acoustic wave resonator (FBAR) filters are promising for the mobile communication devices. Frequency switchable filters are suitable for selecting the vacant frequency bands. Usual polarity unidirectional single layer resonator excites fundamental mode whereas polarity inverted double layer resonator excites second mode. In this study, we considered that polarity inverted structure is easily obtained by applying DC field, which is less than coercive field of BaTiO 3 , to two-layered BST/BaTiO 3 epitaxial films. During the application of -36 V, the two-layered resonator excites fundamental mode. On the other hand, during the application of +36 V, the resonator excites second mode. These results show frequency band switching by DC field.

Film growth of c-axis tilted ScAlN on the sapphire substrate for SAW devices

Tokuda, Shohei; Takayanagi, Shinji; Matsukawa, Mami; Yanagitani, Takahiko

IEEE International Ultrasonics Symposium, IUS 2017/10-2017/10

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Detail

ISSN:19485719

Outline:© 2017 IEEE. Recently, it was shown that heavily doped AlN film possess the high piezoelectricity by Akiyama et al [1]. On the other hand, SAW devices were widely used as filters and sensors. Among them, SAW in ScAlN film is attracting a lot of attention because this SAW devices have high electromechanical coupling coefficient K2. We analyzed the K2 value in Sc 0.4 Al 0.6 N was increased by c-axis tilted angle θ becoming bigger [2]. In this study, changing the angle of c-axis tilted ScAlN films, we have tried to improve the K2 value of SAWs in c-axis tilted ScAlN/R-sapphire.

C-Axis zig-zag polarization inverted ScAlN multilayer for FBAR transformer rectifying antenna

Karasawa, Rei; Yanagitani, Takahiko; Yanagitani, Takahiko; Yanagitani, Takahiko

IEEE International Ultrasonics Symposium, IUS 2017/10-2017/10

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ISSN:19485719

Outline:© 2017 IEEE. Enegy harvesting from surrounding electromagnetic wave have attracted much attention in recent years. Low RF-DC conversion efficiency in the rectenna due to a weak power of electromagnetic wave is a problem. We here report the new type of polarization inverted FBAR transformer for RF amplification in the rectenna. c-Axis zig-zag polarization inverted 12 layer ScAlN was fabricated by glancing sputtering deposition. The 12 layer ScAlN HBAR clearly excites 12th-order shear mode of 1.4 dB at 612 MHz. c-Axis tilt angle of the layers was determined to be 40-45 degrees by an XRD pole figure. This new type of device is promising for high efficiency RF-DC conversion in the rectenna.

C-Axiszig-zag polarization inverted ScAlN multilayer for FBAR transformer rectifying antenna

Karasawa, Rei; Yanagitani, Takahiko; Yanagitani, Takahiko

IEEE International Ultrasonics Symposium, IUS 2017/10-2017/10

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Detail

ISSN:19485719

Outline:© 2017 IEEE. Energy harvesting from surrounding electromagnetic wave can satisfy the increasing demand of trillions of wireless sensors for IoT. RF energy harvesting is generally achieved by RF-DC conversion using a rectifying antenna (called rectenna). For weak RF signal, however, RF-DC conversion efficiency significantly decreases because weak RF signal cannot activate the diode in the rectenna. Therefore, in order to obtain high conversion efficiency for a weak signal, a Dickson charge pump[1] is generally used to increase the RF voltage. However, their low efficiency, poor impedance matching, and large size are the problem. In this study, to overcome this problem, we introduce the RF energy harvester consisting of a new type of polarization inverted FBAR transformer and rectenna. As shown in Fig.1 (a), RF input signal can be increased 7 times when 8 polarization inversion layered FBAR transformer is used. We previously reported various polarization inverted structure such as (0001)/(000-1) ScAlN films [2] and (-1-120)/(11-20) AlN films [3]. We here reports the eight layer of c-axis zig-zag polarization inverted ScAlN stack transformer resonator. [1] A. Parks, et al. Proc. IEEE WiSNET, (2013). [2] M. Suzuki, T. Yanagitani, and H. Odagawa, Appl. Phys. Lett. (2014) [3] M. Suzuki, T. Yanagitani, IUS 2011, 4C-2 (2011).

High electromechanical coefficient kt2=19% thick ScAlN piezoelectric films for ultrasonic transducer in low frequency of 80 MHz

Sano, Ko Hei; Karasawa, Rei; Yanagitani, Takahiko; Yanagitani, Takahiko

IEEE International Ultrasonics Symposium, IUS 2017/10-2017/10

DOIScopus

Detail

ISSN:19485719

Outline:© 2017 IEEE. Ultrasonic in the frequency ranges of 20-100 MHz is not well-developed because of less applications or less suitable piezoelectric materials as shown in Table I. In a photoacoustic imaging, PVDF are usually used for ultrasonic transducers in the 10-50 MHz band. However, their electromechanical coupling coefficient k t 2 of 4% is not enough for the practical uses. To excite ultrasonic in the 20-100 MHz, 125 μm-25 μm thick piezoelectric film is required. It is difficult to fabricate such a thick piezoelectric film without a crack caused by the internal stress during the deposition. A film deposition technique can realize the piezoelectric layer on a complicated surface such as curved or concave surface, which is difficult in the case of the single crystal plate. In this study, we demonstrated high efficient 81 MHz ultrasonic generation by using 43 μm extremely thick ScAlN films.

Film growth of c-axis tilted ScAlN on the sapphire substrate for SAW devices

Tokuda, Shohei; Takayanagi, Shinji; Matsukawa, Mami; Yanagitani, Takahiko

IEEE International Ultrasonics Symposium, IUS 2017/10-2017/10

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Detail

ISSN:19485719

Outline:© 2017 IEEE. ScAlN films are attractive for SAW devices with high electromechanical coupling coefficient K 2 . In previous study, we analyzed K 2 in c-axis-tilted Sc 0.4 Al 0.6 N film / diamond substrate. The K 2 of c-axis-tilted film was increased, compared with that of the c-axis-normally-oriented film. However, it is difficult to perform experiments because diamond substrate are very expensive. In this study, K 2 of SAWs in c-axis tilted ScAlN film / R-sapphire substrate were theoretically analyzed. The K 2 in Rayleigh mode SAW were found to be 3.9% at Ψ = 90° and 3.7% at Ψ = 54°. Next, c-axis tilted ScAlN films were grown on sapphire substrate. c-Axis-33°-tilted ScAlN film was obtained on the R-plane sapphire. Then, IDT/ c-axis-33°-tilted ScAlN / R-sapphire structure was fabricated. The insertion loss of the structure was 34.4 dB. High K 2 was expected to improve the crystalline orientation of the ScAlN films.

A new type wide-frequency-range shear viscosity sensor using c-axis tilted ScAlN thin film on temperature stable AT-cut quartz thick plate

Yamakawa, Yui; Sano, Ko Hei; Karasawa, Rei; Yanagitani, Takahiko

IEEE International Ultrasonics Symposium, IUS 2017/10-2017/10

DOIScopus

Detail

ISSN:19485719

Outline:© 2017 IEEE. In order to study relaxation characteristics of viscoelasticity of the liquid, a wide frequency sweep in the range of MHz to GHz is desired. We, therefore, report a new type HBAR (High overtone Bulk Acoustic Resonator) sensor which makes it possible to operate in a wide frequency range. We choose AT-cut quartz as the substrate whose TCF is zero at room temperature to suppress frequency shifts due to the temperature change. TCF of the HBAR in air is measured to be -3.2 ppm/°C, which demonstrates the great improvement of TCF compared with single ScAlN films (-62 ppm/°C) due to the zero TCF AT-cut quartz substrate. In this study, frequency shifts and frequency peak attenuations were measured for various concentration of glycerin solutions to demonstrate usefulness of the HBAR viscosity measurement.

Books And Publication

Acoustic wave-From Microdevices to Helioseismology (Chapter: Shear mode piezoelectric thin film resonators )

Takahiko Yanagitani

Intech2011-

次世代医療・ヘルスケア機器のデバイス技術と最新開発事例集「横波モード圧電薄膜共振子を用いた抗原抗体反応MEMSセンサの開発」

柳谷隆彦 分担執筆

技術情報協会2014/05-

Patent

Reference Number:1793

圧電体薄膜及びそれを用いた圧電素子(日本, PCT)

柳谷 隆彦, 鈴木 雅視

2016- 92976、2017-201050

Reference Number:1923

トランス及び該トランスを用いたレクテナ(日本)

柳谷 隆彦, 唐澤 嶺

2017- 90568、2018-190800

Research Grants & Projects

Grant-in-aids for Scientific Research Adoption Situation

Research Classification:

Ultrasonic probe using polarity inverted piezoelectric layer

2015/-0-2017/-0

Allocation Class:¥3770000

Research Classification:

Measurement method for polarity-inverted layered piezoelectric thin films using scanning nonlinear dielectric microscopy

2015/-0-2018/-0

Allocation Class:¥4810000

Research Classification:

Piezoelectric thin film MEMS with giant shear electromechanical coupling

2012/-0-2015/-0

Allocation Class:¥4550000

Research Classification:

Development of non contact piezoelectricity measurement system By Brillouin light scattering

2012/-0-2014/-0

Allocation Class:¥4030000

Research Classification:

Study on the piezoelectricity in bone in the MHz range

2012/-0-2015/-0

Allocation Class:¥14950000

Research Classification:

Development of surface acoustic wave piezoelectric films sensors for liquid property measurement

Allocation Class:¥4420000

On-campus Research System

Special Research Project

巨大圧電性薄膜を用いた高感度プローブによる高分解能超音波像装置

2017

Research Results Outline:本研究は、超音波映像装置に応用することを目指して、巨大圧電効果を持つ常誘電体薄膜について数十μm以上の厚膜成長させる技術を確立することを目的としている本研究は、超音波映像装置に応用することを目指して、巨大圧電効果を持つ常誘電体薄膜について数十μm以上の厚膜成長させる技術を確立することを目的としている。RFマグネトロンスパッタ法を用いて膜応力を低減することで厚さ43μmのScAlN厚膜トランスデュ...本研究は、超音波映像装置に応用することを目指して、巨大圧電効果を持つ常誘電体薄膜について数十μm以上の厚膜成長させる技術を確立することを目的としている。RFマグネトロンスパッタ法を用いて膜応力を低減することで厚さ43μmのScAlN厚膜トランスデューサの作製に成功した.ScAlN(0002)X線回折ピークのロッキングカーブ半値幅が4.4ºであり良好な配向性を示した。ネットワークアナライザで縦波変換損失を測定した結果、共振周波数が81MHzのときの電気機械結合係数ktは0.43とPZT系に匹敵する値であった.現在、広く実用化されているPVDF高分子膜と比べるとktがはるかに大きいこと示された。

極性反転多層構造の圧電薄膜を用いた高分解能超音波プロープの実現

2015Collaborator:鈴木雅視

Research Results Outline:超音波顕微鏡装置において画像を高分解能化するには、超音波の高周波化と高出力化が必要である。また、高周波化するには使用する圧電体を薄膜化する。本研究では超音波顕微鏡装置において画像を高分解能化するには、超音波の高周波化と高出力化が必要である。また、高周波化するには使用する圧電体を薄膜化する。本研究では、圧電薄膜を極性反転多層させることにより、周波数を保ったまま耐電圧性を向上させかつ励振面積を大きく...超音波顕微鏡装置において画像を高分解能化するには、超音波の高周波化と高出力化が必要である。また、高周波化するには使用する圧電体を薄膜化する。本研究では、圧電薄膜を極性反転多層させることにより、周波数を保ったまま耐電圧性を向上させかつ励振面積を大きくし、超音波出力を向上させるものである。本研究では、圧電薄膜の中では最も圧電性の大きなScAlN薄膜とZnO薄膜についてスパッタリング成膜法による成長実験を行った。その結果、ZnO薄膜では300℃以上でプラズマ柱外では配向性が良いものが得られ、極性はO極性となることがわかった。これに対して、ScAlN薄膜では室温でプラズマ柱内では配向性が良いものが得られ、極性はAl極性となることを発見した。そこで、この技術を用いてAu上部電極薄膜/Al極性ScAlN薄膜/O極性ZnO薄膜/高配向Ti下部電極薄膜/石英ガラス基板構造の極性反転超音波プローブの作製に成功した。励振面積は2層反転することにより予想どおり2倍となった(50Ω整合時の面積が2倍)。この研究成果に基づいてIEEE超音波国際会議おける受賞(2016年)、超音波シンポジウム奨励賞(2016年)、応用物理学会講演奨励賞(2016年)を受賞した。

横波超音波の固有振動数変動による抗原抗体反応の高感度質量計測

2015Collaborator:鈴木雅視

Research Results Outline:圧電薄膜の固有振動数変動を用いた高感度質量計測センサについて研究を行った。センサの面積を大きくすれば、それに比例して雑音(共振ピークの雑音)を小さくし圧電薄膜の固有振動数変動を用いた高感度質量計測センサについて研究を行った。センサの面積を大きくすれば、それに比例して雑音(共振ピークの雑音)を小さくしていくことができ、測定感度を高くすることができると考えられる。しかし、50Ω計測系と整合させるには...圧電薄膜の固有振動数変動を用いた高感度質量計測センサについて研究を行った。センサの面積を大きくすれば、それに比例して雑音(共振ピークの雑音)を小さくしていくことができ、測定感度を高くすることができると考えられる。しかし、50Ω計測系と整合させるにはセンサのキャパシタンスが定まり、おのずと電極面積が決定される。(膜厚は共振周波数で決定)。本研究では、イオンビームスパッタ法を用いて、酸素イオンビームの照射法を反転させることにより、極性が互いに反転したZnO圧電薄膜を積層成長する技術を開発した。作製した薄膜は高い横波圧電効果を有していることも確認した。これにより、共振周波数を維持したまま膜厚を反転層数倍させ、50Ω整合したままセンサ面積を反転層数倍させたセンサの作製に成功した。

高速負イオン発生抑制成膜による希土類添加AIN薄膜の巨大圧電性発現

2018Collaborator:唐澤嶺, 遠藤結佳, 清水貴博, 正宗千明, 松田有佳

Research Results Outline:本研究では,製法及び不純物含有量の異なるScAl合金ターゲットを用意し,スパッタ成膜時に発生する負イオン照射量及びScAlN薄膜の圧電性へ及ぼす影響を本研究では,製法及び不純物含有量の異なるScAl合金ターゲットを用意し,スパッタ成膜時に発生する負イオン照射量及びScAlN薄膜の圧電性へ及ぼす影響を比較した.アーク溶融ターゲット,焼結ターゲット,電子ビーム溶融ターゲットの3種類のScAl合金ター...本研究では,製法及び不純物含有量の異なるScAl合金ターゲットを用意し,スパッタ成膜時に発生する負イオン照射量及びScAlN薄膜の圧電性へ及ぼす影響を比較した.アーク溶融ターゲット,焼結ターゲット,電子ビーム溶融ターゲットの3種類のScAl合金ターゲットについてスパッタ成膜中の酸素負イオンO-及び窒化炭素負イオンCN-の発生量を計測した.ScAlN薄膜共振子を作製し,電気機械結合係数kt2を推定した結果,アーク溶融ターゲットで20.6%,焼結ターゲットで20.1%,電子ビーム溶融ターゲットで20.3%と,いずれのターゲットを用いても共に先行研究(kt2=18.5%)よりも高い圧電性を示したが,3種類のターゲットに大きな差は見られなかった.

Lecture Course

Course TitleSchoolYearTerm
Frontiers of Electrical Engineering and BioscienceSchool of Advanced Science and Engineering2019spring semester
Frontiers of Electrical Engineering and Bioscience [S Grade]School of Advanced Science and Engineering2019spring semester
Laboratory B on Electrical Engineering and Bioscience (A)School of Advanced Science and Engineering2019spring semester
Laboratory B on Electrical Engineering and Bioscience (B)School of Advanced Science and Engineering2019spring semester
Laboratory B on Electrical Engineering and Bioscience [S Grade]School of Advanced Science and Engineering2019spring semester
Laboratory B on Electrical Engineering and Bioscience [S Grade]School of Advanced Science and Engineering2019spring semester
Laboratory C on Electrical Engineering and BioscienceSchool of Advanced Science and Engineering2019fall semester
Laboratory C on Electrical Engineering and Bioscience [S Grade]School of Advanced Science and Engineering2019fall semester
Project Laboratory ASchool of Advanced Science and Engineering2019spring semester
Project Laboratory A [S Grade]School of Advanced Science and Engineering2019spring semester
Project Laboratory BSchool of Advanced Science and Engineering2019fall semester
Project Laboratory B [S Grade]School of Advanced Science and Engineering2019fall semester
Graduation Thesis ASchool of Advanced Science and Engineering2019spring semester
Graduation Thesis A [S Grade]School of Advanced Science and Engineering2019spring semester
Graduation Thesis BSchool of Advanced Science and Engineering2019fall semester
Graduation Thesis B [Spring]School of Advanced Science and Engineering2019spring semester
Graduation Thesis B [S Grade]School of Advanced Science and Engineering2019fall semester
Graduation Thesis B [Spring] [S Grade]School of Advanced Science and Engineering2019spring semester
Electromagnetism B (3)School of Advanced Science and Engineering2019fall semester
Electromagnetism B : Exercises (3)School of Advanced Science and Engineering2019fall semester
Plasma ElectronicsSchool of Advanced Science and Engineering2019fall semester
Ultrasonic devicesSchool of Advanced Science and Engineering2019fall semester
ElectromagnetismSchool of Advanced Science and Engineering2019spring semester
Electromagnetism [S Grade]School of Advanced Science and Engineering2019spring semester
Electromagnetism: ExercisesSchool of Advanced Science and Engineering2019spring semester
Electromagnetism: Exercises [S Grade]School of Advanced Science and Engineering2019spring semester
Graduation Thesis ASchool of Advanced Science and Engineering2019fall semester
Graduation Thesis BSchool of Advanced Science and Engineering2019spring semester
Master's Thesis (Department of Electrical Engineering and Bioscience)Graduate School of Advanced Science and Engineering2019full year
Research on Molecular Sensors and DevicesGraduate School of Advanced Science and Engineering2019full year
Research on Molecular Sensors and DevicesGraduate School of Advanced Science and Engineering2019full year
Topics on Molecular Sensors and DevicesGraduate School of Advanced Science and Engineering2019spring semester
Advanced Seminar AGraduate School of Advanced Science and Engineering2019spring semester
Advanced Seminar AGraduate School of Advanced Science and Engineering2019spring semester
Advanced Seminar BGraduate School of Advanced Science and Engineering2019fall semester
Advanced Seminar BGraduate School of Advanced Science and Engineering2019fall semester
Seminar on Molecular Sensors and Devices AGraduate School of Advanced Science and Engineering2019spring semester
Seminar on Molecular Sensors and Devices AGraduate School of Advanced Science and Engineering2019spring semester
Seminar on Molecular Sensors and Devices BGraduate School of Advanced Science and Engineering2019fall semester
Seminar on Molecular Sensors and Devices BGraduate School of Advanced Science and Engineering2019fall semester
Seminar on Molecular Sensors and Devices CGraduate School of Advanced Science and Engineering2019spring semester
Molecular Sensors and Devices C: SeminarGraduate School of Advanced Science and Engineering2019spring semester
Seminar on Molecular Sensors and Devices DGraduate School of Advanced Science and Engineering2019fall semester
Molecular Sensors and Devices D: SeminarGraduate School of Advanced Science and Engineering2019fall semester
Master's Thesis (Department of Electrical Engineering and Bioscience)Graduate School of Advanced Science and Engineering2019full year
Research on Molecular Sensors and DevicesGraduate School of Advanced Science and Engineering2019full year