渡部 行男

主要論文

The first proposal and demostration of all oxide FET             

 Y. Watanabe, Epitaxial all-perovskite ferroelectric field effect transistor with a memory retention, Appl. Phys. Lett.66(14), 1770 (1995,April)

 Y. Watanabe, " Field effect transistor with perovskite oxide channel", U.S. Patent No. 5418389 (May 23, 1995).

 Y. Watanabe et al., "Ferroelectrics /(La,Sr)2CuO4 epitaxial hetero-structure with high thermal stability", Appl. Phys. Lett.66(3), 299 (1995,Jan)

  Y. Watanabe et al., "Memory retention and switching speed of ferroelectric field effect in (Pb,La)(Ti,Zr)O3/La2CuO4: Sr heterostructure",     Jpn. J. Appl. Phys. 35(2B), 1564 (1996, Mar)

One of the first reports of resistance switching 

 Y. Watanabe, "A reproducible memory effect in the leakage current of epitaxial ferroelectrics/conductive perovskite hetero-structures", Appl. Phys. Lett.66(1), 28(1995, Jan)

 Y. Watanabe et al, " Ferroelectric/ (La,Sr)2CuO4 epitaxial hetero-structure and hysteretic diode property", Physica 　C235-240, 739(1994,Nov)

 Y. Watanabe, D. Sawamura, and M. Okano, Recurrent local resistance breakdown of an epitaxial BaTiO3 /SrTiO3 heterostructure, Appl. Phys. Lett.72 (19), 2415(1998)

 M. Okano and Y. Watanabe, Nonvolatile programmable two-terminal diodes using ferroelectric semiconductor, Appl. Phys. Lett.76 (2), 233(2000, January).

 Y. Watanabe, J. G. Bednorz et al., Current-driven insulator-conductor transition and nonvolatile memory in chromium-doped SrTiO3 single crystals, Appl. Phys. Lett.78 (23), 3738 (2001).

 M. Okano, Y. Watanabe, and S. W. Cheong, Nonlinear positive temperature coefficient of resistance of Schottky contact on strained epitaxial BaTiO3 film, Appl. Phys. Lett. 82(12), 1923 (2003)　

The first proposal and demostration of feroelectric pn and pp junction and Tunneling

 Y. Watanabe, Tunneling current through a possible all-perovskite oxide pn junction, Phys. Rev. B57(10) (Rapid Commun.) R5563(1998, March)

 Y. Watanabe, Electrical transport through Pb(Zr,Ti)O3 pn and pp heterostructures modulated by bound charges at a ferroelectric surface: Ferroelectric pn diode, Phys. Rev. B 59(17) 11257　(1999).　

 Y. Watanabe and M. Okano, Photodiode properties of epitaxial Pb(Ti,Zr)O3/SrTiO3 ferroelectric heterostructures, Appl. Phys. Lett.78(13), 1906(2001).　

Unconventional diode mechanism

  Y. Watanabe, Unidirectional bulk conduction and the anomalous temperature dependence of drift current under a trap-density gradient, Phys. Rev. B 81,  195210-1-14 (2010).

Prediction and the first demostration of intrisic electron hole layer in defect-free insulating oxides  

 Y. Watanabe, Theoretical stability of the polarization in a thin semiconducting ferroelectric, Phys. Rev. B57(2), 789 (1998, January)

 Y. Watanabe, Theoretical stability of the polarization in insulating-ferroelectric/semiconductor structures, J. Appl. Phys. 83 (4), 2179-2193(1998, Feb);Erratum: J. Appl. Phys. 84(6), 3428 (1998, Sept)

 Y. Watanabe and A. Masuda, Theoretical Stability of Polarization in Metal/Ferroelectric Insulator /Semiconductor and Related Structure, Jpn. J. Appl. Phys. 40(9B) 5610(2001)    https://iopscience.iop.org/article/10.1143/JJAP.40.5610

 Y. Watanabe et al., Surface conduction on insulating BaTiO3 crystal suggesting an intrinsic surface electron layer, Phys. Rev. Lett. 86 (2), 332 (2001).　

 Y. Watanabe, Microscopic derivation of free energy under electric field in ferroelectric and ferroelectric heterostructures containing free carriers,Ferroelectrics,333,57(2006)

Depolarision field

 Y. Watanabe, Examination of permittivity for depolarization field of ferroelectric by ab initio calculation, suggesting hidden mechanisms, Scientific Reports | (2021) 11:2155 |        DOI: 10.1038/s41598-021-81237-0 

 Y. Watanabe, Breakdown of ion-polarization-correspondence and born effective charges: Algebraic formulas of accurate polarization under field, Phys. Rev. Materials 4, 104405 (2020)    DOI: 10.1103/PhysRevMaterials.4.104405

Quantum ferroelectricity

  Y. Watanabe, Ferroelectricity of stress-free and strained pure SrTiO3 revealed by ab initio calculations with hybrid and density functionals, Phys. Rev. B 99, 064107-1-14 (2019).

主要著書  総説他

     Y. Watanabe, Review of Resistance Switching of Ferroelectrics and Oxides in Quest for Unconventional Electronic Mechanisms,Ferroelectrics 349,190 (2007).        ·        https://doi.org/10.1080/00150190701261031

     Y. Watanabe, Physics of ferroelectric interface:an attempt for nano-ferroelectric physics, in  “Ferroelectric Thin Films  - Basic and Device Physics in FerroelectricThin Films for Memory Application -” (Springer, 2005) Topics in Applied Physics 98, ISBN 3-540-24163-9 pp.177-197   https://doi.org/10.1007/978-3-540-31479-0_10

https://link.springer.com/content/pdf/10.1007/978-3-540-31479-0_10.pdf

      Y. Watanabe, Intrinsic Free Electrons/Holes at Polarization Discontinuities and their Implications for Basics of Ferroelectricity and its Origin, Solid State Phenomena Vol. 189 (Ferroics and Multiferroics) (2012) pp. 57-93.  https://www.scientific.net/SSP.189.57      https://doi.org/10.4028/www.scientific.net/SSP.189.57

産業化において本質的役割を担ったもの

  　三菱化学　光磁気記録媒体

　　三菱化学　ピッチ系炭素繊維

主要成立特許　

Y. Watanabe, " Field effect transistor with perovskite oxide channel", U.S. Patent No. 5418389 (May 23, 1995).

Y. Watanabe, "A layer by layer vapor deposition method for forming a high-Tc superconductor thin 　　　　　　　　　　film device",　U. S. Patent No. 5422338 (1995), EU patent(1995)

Y. Watanabe, 日本国特許3186035電界効果素子用積層薄膜および該積層薄膜を用いた電界効果トランジスタ (2001)　

松原覚衛、小柳、吉富、渡部、日本国特許　平07-9714 "光磁気記録媒体".

吉富、小林、佐々木、渡部、日本国特許　平07-75085　"光磁気媒体".

吉富、小林、城阪、渡部、小松、日本国特許2578418 "光磁気記録媒体の製造法" .

吉富、小林、佐々木、渡部、U.S. Patent No. 4743502. "Magnetooptic medium with oxide thin layer",

 EC Patent 、German Patent 、British Patent 、France Patent 、Canadian Patent 

学会活動　経歴等

　　　Princeton U.　Prof. D.C. Tsui 1987-1989　客員研究スタッフ

　　　ATT Bell Lab. Dr. G. A. Thomas  1998  Consultant

　　　IBM Zürich Lab. Dr. G. J. Bednor  2001

　　　　国際高等研究所「電子系の新しい機能」分科会委員

　　　　日本学術振興会　研究開発専門委員会「ナノ物質量子相の科学」委員

　　　　日本学術振興会学術システム研究センター研究員