Tetsuya Tohei

 

Assistant Professor, Institute of Engineering Innovation, The University of Tokyo

 

Address : Bunkyo-ku, Yayoi, 2-11-16, Tokyo 113-8656, Japan.
Phone   : +81-3-5841-7756
E-mail   : tohei[a]sigma.t.u-tokyo.ac.jp

 

 

Current Research :

 

-       STEM observations of atomic and electronic structure of grain boundaries and interfaces

-       First principles calculations of phonon states in crystalline materials

-       Structure and phase transition behavior of ABO3 perovskite oxides and related compounds

 

 


Publication :

Peer reviewed journals

1. T. Tohei, H. Wada, and T. Kanomata

  gNegative magnetocaloric effect at the antiferromagnetic to ferromagnetic transition of Mn3GaCh

  J. Appl. Phys. 94 (2003) 1800-1802

2. T. Tohei, H. Wada, and T. Kanomata

  gLarge magnetocaloric effect of Mn3-xCoxGaCh

  J. Magn. Magn. Mater. 272-276 (2004) E585-586

3. T. Tohei and H. Wada

  gChange in the character of magnetocaloric effect with Ni substitution in Ho(Co1-xNix)2h

  J. Magn. Magn. Mater. 280 (2004) 101-107

4. R. Burriel, L. Tocado, E. Palacios, T. Tohei, and H. Wada

gSquare-shape magnetocaloric effect in Mn3GaCh

  J. Magn. Magn. Mater. 290-291 (2005) 715-718

5. A. Kuwabara, T. Tohei, T. Yamamoto, and I. Tanaka

  gAb initio lattice dynamics and phase transformations of ZrO2h

  Phys. Rev. B 71 (2005) 064301-1-7

6. T. Tohei, A. Kuwabara, T. Yamamoto, F. Oba, and I. Tanaka

  gGeneral Rule for Displacive Phase Transitions in Perovskite Compounds Revisited by First Principles Calculaionsh

  Phys. Rev. Lett. 94 (2005) 035502-1-4@

7. T. Tohei, A. Kuwabara, F. Oba, and I. Tanaka

  gDebye temperature and stiffness of carbon and boron nitride polymorphs by first principles calculationsh

  Phys. Rev. B 73 (2006) 064304-1-7@

8. T. Tohei, H. Moriwake, A. Kuwabara, F. Oba, and I. Tanaka

  gSystematic study of structural instabilities in REMO3 series compounds by first principles calculationsh

  AMTC Letters 1 (2008) 194-195

9. N. Takahashi, T. Mizoguchi, T. Tohei, K. Nakamura, T. Nakagawa, N. Shibata, T. Yamamoto, and Y. Ikuhara

  gFirst principles calculations of vacancy formation energies in S13 pyramidal twin grain boundary of a-Al2O3h

  Mater. Trans. 50 (2009) 1019-1022

10. T. Tohei, H. Moriwake, H. Murata, A. Kuwabara, R. Hashimoto, T. Yamamoto, and I. Tanaka

  gGeometric ferroelectricity in rare-earth compounds RGaO3 and RInO3h

  Phys. Rev. B 79 (2009) 144125-1-5@

11. T. Tohei, T. Mizoguchi, H. Hiramatsu, Y. Kamihara, H. Hosono, and Y. Ikuhara

  gDirect imaging of doped fluorine in LaFeAsO1-xFx superconductor by atomic scale spectroscopyh

  Appl. Phys. Lett.95 (2009) 193107-1-3@

12. H. Ogino, K. Machida, A. Yamamoto, K. Kishio, J. Shimoyama, T. Tohei and Y. Ikuhara

gA new homologous series of iron pnictide oxide superconductors (Fe2As2)(Can+2(Al, Ti)nOy) (n = 2, 3, 4)h

Supercond. Sci. Technol. 23 (2010) 115005-1-5

13. H. Ogino, S. Sato, K. Kishio, J. Shimoyama, T. Tohei, and Y. Ikuhara

gHomologous series of iron pnictide oxide superconductors (Fe2As2)[Can+1(Sc,Ti)nOy] (n = 3,4,5) with extremely thick blocking layersh

Appl. Phys. Lett. 97 (2010) 072506-1-3

14. N. Takahashi, T. Mizoguchi, T. Nakagawa, T. Tohei, I. Sakaguchi, A. Kuwabara, N. Shibata,

T. Yamamoto, N. Ohashi, and Y. Ikuhara

gCr diffusion in alpha-Al2O3: Secondary ion mass spectroscopy and first-principles studyh

  Phys. Rev. B 82 (2010) 174302-1-5

15. H. Hiramatsu, T. Kamiya, T. Tohei, E. Ikenaga, T. Mizoguchi, Y. Ikuhara, K. Kobayashi,

and H. Hosono

gOrigins of Hole Doping and Relevant Optoelectronic Properties of Wide Gap p-Type Semiconductor, LaCuOSeh

J. Am. Chem. Soc. 132 (2010) 15060-15067

16. C. M. Montesa, N. Shibata, T. Tohei, K. Akiyama, Y. Kuromitsu, and Y. Ikuhara

gApplication of Coincidence of Reciprocal Lattice Point Model to Metal/Sapphire Hetero interfacesh

  Mater. Sci. Eng. B 173 (2010) 234-238

17. T. Tohei, T. Mizoguchi, H. Hiramatsu, H. Hosono, and Y. Ikuhara

  gInterface atomic structure of LaCuOSe:Mg epitaxial thin film and MgO substrateh

  Mater. Sci. Eng. B 173 (2010) 229-233

18. T. Tohei, T. Mizoguchi, H. Hiramatsu, Y. Kamihara, H. Hosono, and Y. Ikuhara

gVisualization of Invisible Fluorine Dopants in LaFeAsO1-xFx by Atomic Scale EELS Spectrum Imagingh

AMTC Letters 2 (2010) 252-253

19. C. M. Montesa, N. Shibata, T. Tohei, Y. Ikuhara

  gTEM observation of liquid-phase bonded aluminum-silicon/aluminum nitride hetero interfaceh

  J. Mater. Sci. 46 (2011) 4392-4396

20. T. Mitsuma, T. Tohei, N. Shibata, T. Mizoguchi, T. Yamamoto, Y. Ikuhara

  gStructure of a Sigma=9, [110]/{221} symmetrical tilt grain boundary in SrTiO3h

  J. Mater. Sci. 46 (2011) 4162-4168

21. T. Tohei, T. Mizoguchi, H. Hiramatsu, H. Hosono, and Y. Ikuhara

gInterface and Defect Structures in Epitaxial Thin Films of LaCuOSe and Related Compounds by HAADF-STEM Observationsh

Microsco. Microanal. 17 (2011) 1398-1399

22. H. Moriwake, C. Fisher, A. Kuwabara, T. Tohei, and I. Tanaka

  gFirst-principles Calculations of the Phase Transition in CaTiO3 under Negative Static Pressureh

  J. Korean Phys. Soc. 59 (2011) 2497-2502

23. H. Ogino, Y. Shimizu, N. Kawaguchi, K. Kishio, J. Shimoyama, T. Tohei, and Y. Ikuhara

  gA new iron pnictide oxide (Fe2As2)(Ca5(Mg,Ti)4Oy) and a new phase in the Fe-As-Ca-Mg-Ti-O systemh

  Supercond. Sci. Technol. 24 (2011) 085020-1-6

24. Y. Masubuchi, R. Yamaoka, T. Tohei, T. Mizoguchi, Y. Ikuhara, and S. Kikkawa

  gNanowire of hexagonal gallium oxynitride: Direct observation of its stacking disorder and its long nanowire growthh

  J. Euro. Ceram. Soc. 32 (2012) 1989-1933

25. T. Tohei, T. Mizoguchi, H. Hiramatsu, Y. Kamihara, H. Hosono, and Y. Ikuhara

  gObservation of Microstructures in Doped LaMOX Compounds by Atomic Scale STEM Imagingh

  AMTC Letters 3 (2012) 26-27

26. M. Saitoh, T. Mizoguchi, T. Tohei, and Y. Ikuhara

  gFirst principles calculation of dopant solution energy in HfO2 polymorphsh

  J. Appl. Phys. 112 (2012) 084514-1-7

27. J. Wang, S. Winardi, A. Sugawara-Narutaki, A. Kumamoto, T. Tohei, A. Shimojima, and T. Okubo

  gChain-like nanostructures from anisotropic self-assembly of semiconducting metal oxide nanoparticles with block copolymerh

  Chem. Commun. 48 (2012) 11115-11117

28. T. Matsumoto, R. Ishikawa, T. Tohei, H. Kimura, QW. Yao, HY. Zhao, XL. Wang, DP. Chen, ZX. Cheng, N. Shibata, and Y. Ikuhara

  gMultivariate Statistical Characterization of Charged and Uncharged Domain Walls in Multiferroic Hexagonal YMnO3 Single Crystal Visualized by a Spherical Aberration-Corrected STEMh

  Nano. Lett. 13 (2013) 4594-4601@

29. JZ. Wang, JK. Katahara, A. Kumamoto, T. Tohei, A. Sugawara-Narutaki, A. Shimojima, and T. Okubo

  gSynthesis of string-bean-like anisotropic titania nanoparticles with basic amino acidsh

  RSC Advances 4 (2014) 9233-9235

30. H. Yakita, H. Ogino, T. Okada, A. Yamamoto, K. Kishio, T. Tohei, Y. Ikuhara, Y. Gotoh, H. Fujihisa, K. Kataoka, H. Eisaki, and J. Shimoyama

  gA New Layered Iron Arsenide Superconductor: (Ca,Pr)FeAs2h

  J. Am. Chem. Soc. 136 (2014) 846-849

31. H. Yasumatsu, T. Tohei, and Y. Ikuhara

  gDetermination of Exact Positions of Individual Tungsten Atoms in Unisize Tungsten Oxide Clusters Supported on Carbon Substrate by HAADF-STEM Observationh

  J. Phys. Chem.C 118 (2014) 1706-1711

32. CL. Chen, ZC. Wang, M. Saito, T. Tohei, Y. Takano, and Y. Ikuhara

  gFluorine in Shark Teeth: Its Direct Atomic-Resolution Imaging and Strengthening Functionh

  Angew. Chem. Int. Ed. 53 (2014) 1543-1547

33. T. Tohei, Y. Watanabe, N. Shibata, and Y. Ikuhara

  gFirst Principles Study on Vacancy Formation and Diffusion Behaviors in a-Al2O3 Grain Boundaryh

  AMTC Letters 4 (2014) 134-135

34. K. Takehara, Y. Sato, T. Tohei, N. Shibata, and Y. Ikuhara

  gTitanium enrichment and strontium depletion near edge dislocation in strontium titanate [001]/(110) low-angle tilt grain boundaryh

  J. Mater. Sci. 49 (2014) 3962-3969

35. HY. Zhao, H. Kimura, ZX. Cheng, MR. Osada, JL. Wang, XL. Wang, SX. Dou, Y. Liu, JD. Yu, T. Matsumoto, T. Tohei, N. Shibata, and Y. Ikuhara

  gLarge magnetoelectric coupling in magnetically short-range ordered Bi5Ti3FeO15 filmh

  Sci. Rep. 4 (2014) 5255-1-8

36. YW. Ju, J. Hyodo, A. Inoishi, S. Ida, T. Tohei, YG. So, Y. Ikuhara, and T. Ishihara

  gDouble Columnar Structure with a Nanogradient Composite for Increased Oxygen Diffusivity and Reduction Activityh

  Adv. Energ. Mater. 46 (2014) 1400783-1-8

37. A. Nakamura, S. Furutsuki, S. Nishimura, T. Tohei, Y. Sato, N. Shibata, A. Yamada, and Y. Ikuhara

  gPhase boundary structure of LixFePO4 cathode material revealed by atomic resolution scanning transmission electron microscopyh

  Chem. Mater. 26 (2014)6178-6184

38. T. Katase, K. Endo, T. Tohei, Y. Ikuhara, and H. Ohta

  gRoom-Temperature-Protonation-Driven On-Demand Metal-Insulator Conversion of a Transition Metal Oxideh

  Adv. Electron. Mater. 1 (2015)1500063-1-6

39. T. Tohei, HS. Lee, and Y. Ikuhara

  gFirst principles calculation of thermal expansion of carbon and boron nitrides based on quasi-harmonic approximationh

  Mater. Trans.56 (2015)1452-1456

40. T. Katase, H. Takahashi, T. Tohei, Y. Suzuki, M. Yamanouchi, Y. Ikuhara, I. Terasaki, and H. Ohta

  gSolid-phase epitaxial growth of A-site-ordered perovskite Sr4-xErxCo4O12-d: a room temperature ferrimagnetic p-type semiconductorh

  Adv. Electron. Mater. 1 (2015) 1500199-1-9

41. T. Tohei, Y. Watanabe, N. Takahashi, T. Nakagawa, N. Shibata, and Y. Ikuhara

  gFirst principles study of oxygen diffusion in a a-alumina {10-11} twin grain boundaryh

  Phil. Mag.  accepted for publication

42. T. Moroki, J. Shimoyama, H. Ogino, K. Kishio, J. Roh, T. Tohei, Y. Ikuhara, S. Horii, T. Doi, G. Honda, T. Nagaishi

  gMicrostructures and improved characteristics of Cl-containing YBCO thin films prepared by fluorine-free MOD methodh

  Supercond. Sci. Technol.  accepted for publication

 

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