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大阪大学大学院基礎工学研究科 附属スピントロニクス学術連携研究教育センター

  

研究成果ACHIEVEMENTS

論文・プロシーディング

-2021年-

K. Kudo, S. Yamada, M. Yafuso, T. Kimura, V. K. Lazarov, and K. Hamaya:
“Half-metallic nature of the low-temperature grown Co2MnSi films on SrTiO3

J. Alloys Compd. 854, 155571 (2021).

K. Kudo, M. Yamada, S. Honda, Y. Wagatsuma, S. Yamada, K. Sawano, and K. Hamaya:
“Room-temperature two-terminal magnetoresistance ratio reaching 0.1 % in semiconductor-based lateral devices with L21-ordered Co2MnSi”

Appl. Phys. Lett. (in press).
 
T. Usami, S. Fujii, S. Yamada, Y. Shiratsuchi, R. Nakatani, and K. Hamaya:
“Giant magnetoelectric effect in an L21-ordered Co2FeSi/Pb(Mg1/3Nb2/3)O3-PbTiO3 multiferroic heterostructure”

Appl. Phys. Lett. 118, 142402 (2021).
 
K. Kudo, A. Masago, S. Yamada, L. S. R. Kumara, H. Tajiri, Y. Sakuraba, K. Hono, and K. Hamaya:
“Positive linear magnetoresistance effect in disordered L21B-type Mn2CoAl epitaxial films”

Phys. Rev. B 103, 104427 (2021).

S. Yamada, Y. Teramoto, D. Matsumi, D. Kepaptsouglou, I. Azaceta, T. Murata, K. Kudo, V. K. Lazarov, T. Taniyama, and K. Hamaya:
“Electric-field tunable anisotropic magnetoresistance effect in an epitaxial Co2FeSi/BaTiO3 interfacial multiferroic system”
Phys. Rev. Mater. 5, 014412 (2021).


Y. Wagatsuma, M. M. Alam, K. Okada, M. Yamada, K. Hamaya, K. Sawano:
“Drastic increase in critical thickness for strained SiGe by growth on mesa-patterned Ge-on-Si”
Appl. Phys. Express, 14, 025502 (2021).


A. Yamada, M. Yamada, T. Shiihara, M. Ikawa, S. Yamada, and K. Hamaya:
“Experimental estimation of the spin diffusion length in undoped p-Ge on Fe3Si using vertical spin-valve devices”
J. Appl. Phys. 129, 013901 (2021).



-2020年-

M. Yamada, F. Kuroda, M. Tsukahara, S. Yamada, T. Fukushima, K. Sawano, T. Oguchi, and K. Hamaya:
“Spin injection through the energy-band symmetry matching with high spin polarization in atomically controlled ferromagnet/ferromagnet/semiconductor structures”
NPG Asia Mater. 12, 47 (2020) (Featured Article).


S. Kaneta, M. Yamada, S. Sato, S. Arai, L. D. Anh, K. Hamaya, and S. Ohya:
“Enhancement of the spin Hall angle by the interdiffusion of atoms in Co2FeAl0.5Si0.5/n-Ge heterostructures”

Phys. Rev. Applied 14, 024096 (2020).

T. Naito, M. Yamada, S. Yamada, K. Sawano, and K. Hamaya:
“Suppression of Donor-Driven Spin Relaxation in Strained Si0.1Ge0.9

Phys. Rev. Applied 13, 054025 (2020).

Y. Shimanuki, S. Yamada, A. Masago, T. Ishibe, K. Kudo, Y. Nakamura, and K. Hamaya:
“Control of thermoelectric properties in Mn-substituted Fe2TiSi epilayers”

Phys. Rev. B 102, 054203 (2020).

T. Shiihara, M. Yamada, M. Honda, A. Yamada, S. Yamada, and K. Hamaya:
“Spin transport in antimony-doped germanium detected using vertical spin-valve structures”

Appl. Phys. Express 13, 023001 (2020).

Y. Wagatsuma, M. M. Alam, K. Okada, Y. Hoshi, M. Yamada, K. Hamaya, K. Sawano:
“Crack formation in strained SiGe grown on Ge-on-Si (111) and its suppression by patterning substrates”

Mat. Sci. Semicon. Proc. 117, 105153 (2020).

M. Honda, T. Shiihara, M. Yamada, S. Yamada, K. Hamaya:
“Germanium pn junctions between ferromagnetic CoFe and Fe3Si layers for spintronic applications”

Mat. Sci. Semicon. Proc. 116, 105066 (2020).

T. Naito, M. Yamada, S. Yamada, T. Kanashima, K. Sawano, and K. Hamaya:
“Inverse local magnetoresistance effect up to room temperature in ferromagnet-semiconductor lateral spin-valve devices”

Mat. Sci. Semicon. Proc. 113, 105046 (2020).

S. Yamada, H. Higashi, T. Kanashima, and K. Hamaya:
“Growth of ferromagnetic Co2FeSi films on flexible Ge(111)”

Mat. Sci. Semicon. Proc. 112, 104997 (2020).

Y. Shimanuki, K. Kudo, T. Ishibe, A. Masago, S. Yamada, Y. Nakamura, and K. Hamaya:
“Thermoelectric properties of single-phase full-Heusler alloy Fe2TiSi films with D03-type disordering”

J. Appl. Phys. 127, 055106 (2020).

M. Ishikawa, Y. Saito, and K. Hamaya:
“Study of spin transport and magnetoresistance effect in silicon-based lateral spin devices for spin-MOSFET applications” (Review)

J. Magn. Soc. Jpn. 44, 56-63 (2020).

K. Sawano, Y. Wagatsuma, M. M. Alam, K. Omata, K. Niikura, S. Shibata, Y. Hoshi, M. Yamada, and K. Hamaya:
“Strain engineering of Si/Ge heterostructures on Ge-on-Si platform”
ECS Trans. 98 (5), 267 (2020).


Y. Wagatsuma, M. M. Alam, K. Okada, Y. Hoshi, M. Yamada, K. Hamaya, and K. Sawano:
“Increased critical thickness for strained SiGe on Ge-on-Si(111)”
ECS Trans. 98 (5), 499 (2020).


R. Jansen, A. Spiesser, Y. Fujita, H. Saito, S. Yamada, K. Hamaya, and S. Yuasa:
“Proximity exchange coupling across an MgO tunnel barrier detected via spin precession”
Proc. SPIE 11470 114700Z (2020).



-2019年-

K. Kudo, Y. Hamazaki, S. Yamada, S. Abo, Y. Gohda, and K. Hamaya:
“Great differences between low-temperature grown Co2FeSi and Co2MnSi films on single-crystalline oxides”
ACS Appl. Electron. Mater. 1, 2371 (2019).

A. Spiesser, Y. Fujita, H. Saito, S. Yamada, K. Hamaya, W. Mizubayashi, K. Endo, S. Yuasa, and R. Jansen:
“Quantification of spin drift in devices with a heavily doped Si channel”
Phys. Rev. Applied 11, 044020 (2019).

S. Yamada, S. Kobayashi, A. Masago, L. S. R. Kumara, H. Tajiri, S. Abo, T. Fukushima, Y. Sakuraba, K. Hono, T. Oguchi, and K. Hamaya:
“Experimental verification of the origin of the positive linear magnetoresistance in CoFe(V1-xMnx)Si Heusler alloys”
Phys. Rev. B 100, 195137 (2019).

R. Jansen, A. Spiesser, H. Saito, Y. Fujita, S. Yamada, K. Hamaya, and S. Yuasa:
“Proximity exchange coupling in a Fe/MgO/Si tunnel contact detected by the inverted Hanle effect”
Phys. Rev. B, 100, 174432 (2019).

Y. Fujita, M. Yamada, M. Tsukahara, T. Naito, S. Yamada, K. Sawano, and K. Hamaya:
“Nonmonotonic bias dependence of local spin accumulation signals in ferromagnet/semiconductor lateral spin-valve devices”
Phys. Rev. B 100, 024431 (2019).

K. Kudo, S. Yamada, J. Chikada, Y. Shimanuki, T. Ishibe, S. Abo, H. Miyazaki, Y. Nishino, Y. Nakamura, and K. Hamaya:
“Significant reduction in thermal conductivity in Si-substituted Fe2VAl epilayers”
Phys. Rev. B 99, 054201 (2019).

A. Spiesser, Y. Fujita, H. Saito, S. Yamada, K. Hamaya, S. Yuasa, and R. Jansen:
“Hanle spin precession in a two-terminal lateral spin valve”
Appl. Phys. Lett. 114, 242401 (2019).

M. Ishikawa, M. Tsukahara, S. Honda, Y. Fujita, M. Yamada, Y. Saito, T. Kimura, H. Itoh, and K. Hamaya:
“Crystal orientation effect on spin injection/detection efficiency in Si lateral spin-valve devices”
J. Phys. D: Appl. Phys. 52, 085102 (2019).

M. Alam, Y. Wagatsuma, K. Okada, Y. Hoshi, M. Yamada, K. Hamaya, and K. Sawano:
“Critical thickness of strained Si1-xGex on Ge(111) and Ge-on-Si(111)”
Appl. Phys. Express 12, 081005 (2019).

M. Tsukahara, M. Yamada, T. Naito, S. Yamada, K. Sawano, V. K. Lazarov, and K. Hamaya:
“Room-temperature local magnetoresistance effect in n-Ge devices with low-resistive Schottky-tunnel contacts”
Appl. Phys. Express 12, 033002 (2019).

H. Miyazaki, S. Tateishi, M. Matsunami, K. Soda, S. Yamada, K. Hamaya, and Y. Nishino:
Direct observation of pseudo-gap electronic band structure in the Heusler-type Fe2VAl thin film
J. Electron. Spectrosc. Relat. Phenom. 232, 1-4 (2019).

S. Yamada, S. Kobayashi, K. Arima and K. Hamaya:
Magnetic and transport properties of Co1+xFeV1-xSi epitaxial films grown by molecular beam epitaxy
IEEE Trans. Magn. 55, 2 (2019).


-2018年-

S. Yamada, S. Kobayashi, F. Kuroda, K. Kudo, S. Abo, T. Fukushima, T. Oguchi, and K. Hamaya:
“Magnetic and transport properties of equiatomic quaternary Heusler CoFeVSi epitaxial films”
Phys. Rev. Mater. 2, 124403 (2018).

R. Jansen, A. Spiesser, H. Saito, Y. Fujita, S. Yamada, K. Hamaya, and S. Yuasa:
“Nonlinear Electrical Spin Conversion in a Biased Ferromagnetic Tunnel Contact”
Phys. Rev. Applied 10, 064050 (2018).

K. Arima, F. Kuroda, S. Yamada, T. Fukushima, T. Oguchi, and K. Hamaya:
“Anomalous Hall conductivity and electronic structures of Si-substituted Mn2CoAl epitaxial films”
Phys. Rev. B 97, 054427 (2018).

B. Kuerbanjiang, Y. Fujita, M. Yamada, S. Yamada, A. M. Sanchez, P. J. Hasnip, A. Ghasemi, D. Kepaptsoglou, G. Bell, K. Sawano, K. Hamaya, and V. K. Lazarov:
“Correlation between spin transport signal and quality of the Heusler-alloy/semiconductor interface in lateral spin-valve devices”
Phys. Rev. B 98, 115304 (2018).

B. Kuerbanjiang, C. Love, D. Kepaptsoglou, Z. Nedelkoski, S. Yamada, A. Ghasemi, Q. M. Ramasse, K. Hamaya, S. A. Cavill, V. K. Lazarov:
“Effect of annealing on the structure and magnetic properties of Co2FeAl0.5Si0.5 thin films on Ge(111)”
J. Alloys Compd. 748, 323 (2018).

S. Oki, Y. Sasaki, Y. Kasatani, S. Yamada, S. Mizukami, Y. Nozaki, and K. Hamaya:
“Modulation of magnetization dynamics in an epitaxial Heusler ferromagnet due to pure spin current in a laterally configured structure”
J. Phys.: Conden. Matter. 30, 255802 (2018).

S. Glover, T. Saerbeck, B. Kuerbanjiang, A. Ghasemi, D. Kepaptsoglou, Q. Ramasse, S. Yamada, K. Hamaya, T. Hase, V. Lazarov, and G. Bell:
“Magnetic and structural depth profiles of Heusler alloy Co2FeAl0.5Si0.5 epitaxial films on Si(111)”

J. Phys.: Conden. Matter. 30, 065801 (2018).


T. Naito, M. Yamada, M. Tsukahara, S. Yamada, K. Sawano, and K. Hamaya:
“Pure spin current transport in a SiGe alloy”
Appl. Phys. Express 11, 053006 (2018).

M. Yamada, Y. Fujita, S. Yamada, K. Sawano, and K. Hamaya:
“Spin absorption effect at ferromagnet/Ge Schottky-tunnel contacts”
Materials 11, 150 (2018).

K. Hamaya, Y. Fujita, M. Yamada, M. Kawano, S. Yamada, and K. Sawano:
“Spin transport and relaxation in germanium”
J. Phys. D: Appl. Phys. 51, 393001 (2018) (Topical Review).

M. Yamada, T. Naito, M. Tsukahara, S. Yamada, K. Sawano, and K. Hamaya:
“Observation of local magnetoresistance signals in a SiGe-based lateral spin-valve device”
Semicond. Sci. Technol. 33, 114009 (2018).

T. Shiihara, S. Oki, S. Sakai, M. Ikawa, S. Yamada, and K. Hamaya:
“Epitaxial growth of Sb-doped Ge layers on ferromagnetic Fe3Si for vertically semiconductor spintronic devices”
Semicond. Sci. Technol. 33, 104008 (2018).

H. Higashi, K. Kudo, K. Yamamoto, S. Yamada, T. Kanashima, I. Tsunoda, H. Nakashima, and K. Hamaya:
Electrical properties of pseudo-single-crystalline Ge films grown by Au-induced layer exchange crystallization at 250 oC
J. Appl. Phys. 123, 215704 (2018).

M. Ishikawa, M. Tsukahara, M. Yamada, Y. Saito, and K. Hamaya:
Local magnetoresistance at room temperature in Si<100> devices

IEEE Trans. Magn. 54, 11 (2018).

K. Kudo, S. Yamada, J. Chikada, Y. Shimanuki, Y. Nakamura, and K. Hamaya:
Effect of Fe-V nonstoichiometry on electrical and thermoelectric properties of Fe2VAl films
Jpn. J. Appl. Phys. 57, 040306 (2018). (Rapid Communications).


-2017年-

M. Kawano, M. Ikawa, K. Santo, S. Sakai, H. Sato, S. Yamada, and K. Hamaya:
“Electrical detection of spin accumulation and relaxation in p-type germanium”
Phys. Rev. Mater. 1, 034604 (2017).


M. Yamada, Y. Fujita, M. Tsukahara, S. Yamada, K. Sawano, and K. Hamaya:
"Large impact of impurity concentration on spin transport in degenerate n-Ge"

Phys. Rev. B 95, 161304(R) (2017). (Rapid Communications).
Y. Fujita, M. Yamada, M. Tsukahara, T. Oka, S. Yamada, T. Kanashima, K. Sawano, and K. Hamaya:
"Spin Transport and Relaxation up to 250 K in Heavily Doped n-Ge Detected Using Co2FeAl0.5Si0.5 Electrodes"

Phys. Rev. Applied 8, 014007 (2017).

A. Spiesser, H. Saito, Y. Fujita, S. Yamada, K. Hamaya, S. Yuasa, R. Jansen:
"Giant Spin Accumulation in Silicon Nonlocal Spin-Transport Devices"
Phys. Rev. Applied 8, 064023 (2017).

M. Ishikawa, T. Oka, Y. Fujita, H. Sugiyama, Y. Saito, and K. Hamaya:
"Spin relaxation through lateral spin transport in heavily doped n-type silicon"

Phys. Rev. B 95, 115302 (2017).

H. Higashi, M. Nakano, K. Kudo, Y. Fujita, S. Yamada, T. Kanashima, I.Tsunoda, H. Nakashima, and K. Hamaya:
"A crystalline germanium flexible thin-film transistor"
Appl. Phys. Lett. 111, 222105 (2017).

S. Yamada, K. Kudo, R. Okuhata, J. Chikada, Y. Nakamura, and K. Hamaya:
Low thermal conductivity of thermoelectric Fe2VAl films
Appl. Phys. Express 10, 115802 (2017).

M. Yamada, M. Tsukahara, Y. Fujita, T. Naito, S. Yamada, K. Sawano, and K. Hamaya:
"Room-temperature spin transport in n-Ge probed by four-terminal nonlocal measurements"
Appl. Phys. Express 10, 093001 (2017) (Spotlights).


T. Kanashima, R. Yamashiro, M. Zenitaka, K. Yamamoto, D. Wang, J. Tadano, S. Yamada, H. Nohira, H. Nakashima, and K. Hamaya:
"Electrical properties of epitaxial Lu- or Y-doped La2O3/La2O3/Ge high-k gate-stacks"

Mat. Sci. Semicon. Proc. 70, 260-264 (2017).

M. Yamada, Y. Fujita, S. Yamada, T. Kanashima, K. Sawano, and K. Hamaya:
"Control of electrical properties in Heusler-alloy/Ge Schottky tunnel contacts by using phosphorous δ-doping with Si-layer insertion"

Mat. Sci. Semicon. Proc. 70, 83-85 (2017).

K. Kasahara, H. Higashi, M. Nakano, Y. Nagatomi, K. Yamamoto, H. Nakashima, and K. Hamaya:
"Effect of post annealing on electrical properties of pseudo-single-crystalline germanium films fabricated on glass substrates"

Mat. Sci. Semicon. Proc. 70, 68-72 (2017).

S. Sakai, M. Kawano, M. Ikawa, H. Sato, S. Yamada, and K. Hamaya:
"Low-temperature growth of fully epitaxial CoFe/Ge/Fe3Si layers on Si for vertical-type semiconductor spintronic devices"
Semicond. Sci. Technol. 32, 094005 (2017).

M. Ikawa, M. Kawano, S. Sakai, S. Yamada, T. Kanashima, and K. Hamaya:
"Influence of the Ge diffusion on the magnetic and structual properties in Fe3Si and CoFe epilayers grown on Ge"

J. Cryst. Growth 468, 676-679 (2017).


S. Oki, T. Kurokawa, S. Honda, S. Yamada, T. Kanashima, H. Itoh, and K. Hamaya:
"Robust spin-current injection in lateral spin valves with two-terminal Co2FeSi spin injectors"
AIP Advances 7, 055808 (2017).


A. Spiesser, H. Saito, Y. Fujita, S. Yamada, K. Hamaya, S. Yuasa and R. Jansen:
“Spin signals in Si non-local transport devices with giant spin accumulation”
Proceedings of SPIE 10357 ,103570C (2017).


-2016年-

Z. Nedelkoski, B. Kuerbanjiang, S. E. Glover, A. Sanchez, D. Kepaptsoglou, A. Ghasemi, C. W. Burrows, S. Yamada, K. Hamaya, Q. Ramasse, P. Hasnip, T. Hase, G. Bell, A. Hirohata, and V. Lazarov:
"Realisation of magnetically and atomically abrupt harlfmetal/semiconductor interfaces:Co2FeAl0.5Si0.5/Ge(111)"
Scientific Reports 6, 37282 (2016).


K. Hamaya, T. Kurokawa, S. Oki, S. Yamada, T. Kanashima, and T. Taniyama:
"Direct evidence for suppression of the Kondo effect due to pure spin current"
Phys. Rev. B 94, 140401(R) (2016). (Rapid Communications)


Y. Fujita, M. Yamada, S. Yamada, T. Kanashima, K. Sawano, and K. Hamaya:
"Temperature independent spin relaxation in heavily doped n-type germanium"
Phys. Rev. B 94, 245302 (2016).


S. Yamada, S. Honda, J. Hirayama, M. Kawano, K. Santo, K. Tanikawa, T. Kanashima, H. Itoh, and K. Hamaya:
"Magnetic properties and interfacial characteristics of all-epitaxial Heusler-compound stacking structures"
Phys. Rev. B 94, 094435 (2016).


M. Kawano, K. Santo, M. Ikawa, S. Yamada, T. Kanashima, and K. Hamaya:
"Spin transport in p-Ge through a vertically stacked Ge/Fe3Si junction"
Appl. Phys. Lett. 109, 022406 (2016).


B. Kuerbanjiang, Z. Nedelkoski, D. Kepaptsoglou, A. Ghasemi, S. E. Glover, S. Yamada, T. Saerbeck, Q. M. Ramasse, P. J. Hasnip, T. P. Anslem Hase, G. R. Bell, K. Hamaya, A. Hirohata, and V. K. Lazarov:
"The role of chemical structure on the magnetic and electronic properties of Co2FeAl0.5Si0.5/Si(111) interface"
Appl. Phys. Lett. 108, 172412 (2016).


Z. Nedelkoski, A. M. Sanchez, A. Ghasemi, K. Hamaya, R. F. L. Evans, G. R. Bell, A. Hirohata, and V. K. Lazarov:
"The antiphase boundary in half-metallic Heusler alloy Co2Fe(Al,Si): atomic structure, spin polarization reversal and domain wall effects"
Appl. Phys. Lett. 109, 222405 (2016).


T. Yamaguchi, R. Moriya, S. Oki, S. Yamada, S. Masubuchi, K. Hamaya, and T. Machida:
"Spin injection into multilayer graphene from highly spin-polarized Co2FeSi Heusler alloy"
Appl. Phys. Express 9, 063006 (2016).


Z. Nedelkoski, D. Kepaptsoglou, A. Ghasemi, B. Kuerbanjiang, P. J. Hasnip, S. Yamada, K. Hamaya, Q. M. Ramasse, A. Hirohata, and V. K. Lazarov:
"Controlling the half-metallicity of Heusler/Si(111) interfaces by a monolayer of Si-Co-Si"

J. Phys.: Conden. Matter. 28, 395003 (2016).


M. Kawano, M. Ikawa, K. Arima, S. Yamada, T. Kanashima, and K. Hamaya:
"All-epitaxial Co2FeSi/Ge/Co2FeSi trilayers fabricated by Sn-induced low-temperature epitaxy"
J. Appl. Phys. 119, 045302 (2016).


K. Sawano, Y. Hoshi, S. Kubo, K. Arimoto, J. Yamanaka, K. Nakagawa, K. Hamaya, M. Miyao, and Y. Shiraki:
"Structual and electrical properties of Ge(111) films grown on Si(111) substrates and application to Ge(111)-on-insulator"
Thin Solid Films 613, 24-28 (2016)


S. Yamada, K. Tanikawa, J. Hirayama, T. Kanashima, T. Taniyama, and K. Hamaya:
"Exchange coupling in metallic multilayers with a top FeRh layer"
AIP advances 6, 056115 (2016).
.

Y. Fujita, M. Yamada, Y. Nagatomi, K. Yamamoto, S. Yamada, K. Sawano, T. Kanashima, H. Nakashima, and K. Hamaya:
"A low-temperature fabricated gate-stack structure for Ge-based MOSFET with ferromagnetic epitaxial Heusler-alloy/Ge electrodes"
Jpn. J. Appl. Phys. 55, 063001 (2016).


K. Hamaya, M. Kawano, Y. Fujita, S. Oki, and S. Yamada:
"Finely Controlled Approaches to Formation of Heusler-Alloy/Semiconductor Heterostructures for Spintronics"
Mater. Trans. 57(6), 760-766 (2016).


K. Hamaya, S. Yamada, K. Kasahara, and T. Kanashima:
"Finely controlled heterointerfaces between Ge(111) and metallic alloys or insulators for next generation Ge-based devices"
ECS Trans. 75(8), 651-659 (2016).


D. Kepaptsoglou, Z. Nedelkoski, B. Kuerbanjiang, A. Ghasemi, S. Yamada, K. Hamaya, A. Hirohata, Q. M. Ramasse, and V. K. Lazarov:
"Atomic and electronic structure study of a Co2FeAl0.5Si0.5 half metal thin film on Si(111)"
Microsc. Microanal. 22(S3), 1524-1525 (2016).



-2015年-

S. Yamada, K. Tanikawa, J. Hirayama, T. Kanashima, T. Taniyama, and K. Hamaya:
"Low-temperature B2 ordering and magnetic properties of Fe100-xRhx films on bcc alloys"
Phys. Rev. B 92, 094416 (2015).


K. Kasahara, Y. Nagatomi, K. Yamamoto, H. Higashi, M. Nakano, S. Yamada, D. Wang, H. Nakashima, and K. Hamaya:
"Electrical properties of pseudo-single-crystalline germanium thin-film-transistors fabricated on glass substrates"
Appl. Phys. Lett. 107, 142102 (2015).


M. Ishikawa, H. Sugiyama, T. Inokuchi, K. Hamaya and Y. Saito:
"Spin transport and accumulation in n+-Si using Heusler compound Co2FeSi/MgO tunnel contacts"
Appl. Phys. Lett. 107, 092402 (2015).


H. Higashi, K. Kasahara, K. Kudo, H. Okamoto, K. Moto, J. -H Park, S. Yamada, T. Kanashima, M. Miyao,
I. Tsunoda and K. Hamaya:
"A pseudo-single-crystalline germanium film for flexible electronics"
Appl. Phys. Lett. 106, 041902 (2015).

Kento Yamasaki, Soichiro Oki, Shinya Yamada, Takeshi Kanashima, and Kohei Hamaya:
"Spin-related thermoelectric conversion in lateral spin-valve devices with single-crystalline Co2FeSi electrodes"
Appl. Phys. Express 8, 043003 (2015).

T. Kanashima, H. Nohira, M. Zenitaka, Y. Kajihara, S. Yamada, and K. Hamaya:
"Effect of atomic-arrangement matching on La2O3/Ge heterostructures for epitaxial high-k-gate-stacks"
J. Appl. Phys. 118, 225302 (2015).


Y. Saito, M. Ishikawa, H. Sugiyama, T. Inokuchi, K. Hamaya and N. Tezuka:
"Correlation between amplitude of spin accumulation signals investigated by Hanle effect measurement and effective junction barrier height in CoFe/MgO/n+-Si junctions"
J. Appl. Phys. 117, 17C707 (2015).



-2014年-

S. Yamada, K. Tanikawa, S. Oki, M. Kawano, M. Miyao and K. Hamaya:
"Improvement of magnetic and structural stabilities in high-quality Co2FeSi1-xAlx/Si heterointerfaces"
Appl. Phys. Lett. 105, 071601 (2014).


K. Kasahara, S. Yamada, T. Sakurai, K. Sawano, H. Nohira, M. Miyao and K. Hamaya:
"Reliable reduction of Fermi-level pinning at atomically matched metal/Ge interfaces by sulfer treatment"
Appl. Phys. Lett. 104, 172109 (2014).


J. -H Park, K. Kasahara, K. Hamaya, M. Miyao and T. Sadoh:
"High carrier mobility in orientation-controlled large-grain Ge directly formed on flexible plastic by nucleation-controlled gold-induced-crystallization"
Appl. Phys. Lett. 104, 252110 (2014)


Y. Kasatani, S. Yamada, H. Itoh, M. Miyao, K. Hamaya and Y. Nozaki:
"Large anisotropy of Gilbert damping constant in L21-ordered Co2FeSi films"
Appl. Phys. Express 7, 123001 (2014).

K. Kasahara, Y. Fujita, S. Yamada, K. Sawano, M. Miyao and K. Hamaya:
"Greatly enhanced generation efficiency of pure spin currents in Ge using Heusler compound Co2FeSi electrodes"
Appl. Phys. Express 7, 033002 (2014).

Y. Saito, M. Ishikawa, T. Tanamoto, H. Sugiyama, T. Inokuchi, K. Hamaya and N. Tezuka:
"Local magnetoresistance through Si and its bias voltage in ferromagnet/MgO/SOI lateral spin valves"
J. Appl. Phys. 115, 17C514 (2014).

K. Hamaya, G. Takemoto, Y. Baba, K. Kasahara, S. Yamada, K. Sawano and M. Miyao:
"Room-temperature electrical creation of spin accumulation in n-Ge using highly resistive Fe3Si/n+-Ge Schottky tunnel contacts"
Thin Solid Films 557, 382-385 (2014).


K. Tanikawa, S. Oki, S. Yamada, M. Kawano, M. Miyao and K. Hamaya:
"High-quality Co2FeSi0.5Al0.5/Si heterostructures for spin injection in silicon spintronic devices"
Thin Solid Films 557, 390-393 (2014).

Y. Fujita, S. Yamada, Y. Maeda, M. Miyao and K. Hamaya:
"A magnetic tunnel junction with an L21-ordered Co2FeSi electrode formed by all room-temperature fabrication processes"
Thin Solid Films 557, 386-389 (2014).

K. Sawano, Y. Hoshi, S. Endo, T. Nagashima, K. Arimoto, J. Yamanaka, K. Nakagawa, S. Yamada, K. Hamaya, M. Miyao and Y. Shiraki:
"Formation of Ge(111) on insulator by Ge epitaxy on Si(111) and layer transfer"
Thin Solid Films 557, 76-79 (2014).


K. Hamaya:
"Germanium Spintronics with Highly Spin-polarized Electrodes"
Workshop Digest of 2014 Asia-Pacific Workshop on Fundamentals and Applications of Advanced Semiconductor Devices, 40-43 (2014).


J. Hirayama, K. Tanikawa, M. Kawano, S. Yamada, M. Miyao, and K. Hamaya:
"An all epitaxial Fe3Si/FeSi/Co2FeSi trilayer grown by room-temperature molecular beam epitaxy"
IEEE Trans. Magn. 50, 11 (2014).


-過去の代表的な論文-

S. Yamada, J. Sagar, S. Honda, L. Lari, G. Takemoto, H. Itoh, A. Hirohata, K. Mibu, M. Miyao, and K. Hamaya:
"Room-temperature structural ordering of a Heusler-compound Fe3Si"
Phys. Rev. B 86, 174406 (2012).

K. Hamaya, N. Hashimoto, S. Oki, S. Yamada, M. Miyao, and T. Kimura:
"Estimation of the spin polarization for Heusler-compound thin films by means of nonlocal spin-valve measurements: Comparison of Co2FeSi and Fe3Si"
Phys. Rev. B 85, 100404(R) (2012). (Rapid Communications)

T. Kimura, N. Hashimoto, S. Yamada, M. Miyao, and K. Hamaya:
"Room-temperature generation of giant pure spin currents using epitaxial Co2FeSi spin injectors"
NPG Asia Mater. 4, e9 (2012).

K. Kasahara, Y. Baba, K. Yamane, S. Yamada, Y. Ando, Y. Hoshi, K. Sawano, M. Miyao, and K. Hamaya:
"Spin accumulation created electrically in an n-type germanium channel using Schottky tunnel contacts"
J. Appl. Phys. 111, 07C503 (2012).

S. Yamada, K. Tanikawa, M. Miyao, and K. Hamaya:
"Atomically controlled epitaxial growth of single-crystalline germanium films on a metallic silicide"
Cryst. Growth & Des. 12, 4703-4707 (2012). (Communication)

K. Kasahara, S. Yamada, K. Sawano, M. Miyao, and K. Hamaya:
"Mechanism of Fermi Level Pinning at Metal/Germanium Interfaces"
Phys. Rev. B 84, 205301 (2011).

K. Hamaya, T. Murakami, S. Yamada, K. Mibu, and M. Miyao:
"Local structural ordering in low-temperature-grown epitaxial Fe3+xSi1-x films on Ge(111)"
Phys. Rev. B 83, 144411 (2011). (Editors’ suggestions)

Y. Ando, Y. Maeda, K. Kasahara, S. Yamada, Y. Hoshi, K. Sawano, K. Izunome, A. Sakai, M. Miyao, and K. Hamaya:
"Electric-field control of spin accumulation signals in silicon at room temperature"
Appl. Phys. Lett. 99, 132511 (2011). (Research Highlights)

K. Yamane, K. Hamaya, Y. Ando, Y. Enomoto, K. Kasahara, K. Yamamoto, T. Sadoh, and M. Miyao:
"Effect of atomically controlled interfaces on Fermi-level pinning at metal/Ge interfaces"
Appl. Phys. Lett. 96, 162104 (2010).

S. Yamada, K. Hamaya, K. Yamamoto, T. Murakami, K. Mibu, and M. Miyao:
"Significant growth- temperature dependence of ferromagnetic properties for Co2FeSi/Si(111) prepared by low-temperature molecular beam epitaxy"
Appl. Phys. Lett. 96, 082511 (2010).

K. Hamaya, M. Kitabatake, K. Shibata, M. Jung, S. Ishida, T. Taniyama, K. Hirakawa, Y. Arakawa, and T. Machida:
"Spin-Related Current Suppression in a Semiconductor-Quantum-Dot Spin-Diode Structure"
Phys. Rev. Lett. 102, 236806 (2009).

Y. Ando, K. Hamaya, K. Kasahara, Y. Kishi, K. Ueda, K. Sawano, T. Sadoh and M. Miyao:
"Electrical injection and detection of spin-polarized electrons in silicon through an Fe3Si/Si Schottky tunnel barrier"
Appl. Phys. Lett. 94, 182105 (2009).

K. Hamaya, H. Itoh, O. Nakatsuka, K. Ueda, K. Yamamoto, M. Itakura, T. Taniyama, T. Ono, and M. Miyao:
"Ferromagnetism and Electronic structures of Nonstoichiometric Heusler- Alloy Fe3-xMnxSi Epilayers Grown on Ge(111)"
Phys. Rev. Lett. 102, 137204 (2009).

K. Hamaya, M. Kitabatake, K. Shibata, M. Jung, M. Kawamura, S. Ishida, T. Taniyama, K. Hirakawa, Y. Arakawa, and T. Machida:
"Oscillatory Changes in the Tunneling Magnetoresistance Effect in Semiconductor Quantum-Dot Spin Valves"
Phys. Rev. B 77, 081302(R) (2008). (Rapid Communications)

K. Hamaya, M. Kitabatake, K. Shibata, M. Jung, M. Kawamura, K. Hirakawa, T. Machida, T. Taniyama, S. Ishida, and Y. Arakawa:
"Kondo effect in a semiconductor quantum dot coupled to ferromagnetic electrodes"
Appl. Phys. Lett. 91, 232105 (2007).

K. Hamaya, S. Masubuchi, M. Kawamura, T. Machida, M. Jung, K. Shibata, K. Hirakawa, T. Taniyama, S. Ishida, Y. Arakawa:
"Spin transport through a single self-assembled InAs quantum dot with ferromagnetic leads"
Appl. Phys. Lett. 90, 053108 (2007).

K. Hamaya, T. Taniyama, Y. Kitamoto, T. Fujii, and Y. Yamazaki:
"Mixed magnetic phases in (Ga,Mn)As epilayers"
Phys. Rev. Lett. 94, 147203 (2005).

K. Hamaya, T. Taniyama, Y. Kitamoto, R. Moriya, and H. Munekata:
"Magnetotransport study of temperature dependent magnetic anisotropy in a (Ga,Mn)As epilayer"
J. Appl. Phys. 94, 7657 (2003).