2000 Fiscal Year Annual Research Report

強誘電性および導電性の交代層をもつビスマス層状構造酸化物デバイスの開発

Research Project

Project/Area Number	11555163
Research Institution	University of Tokyo
Principal Investigator	宮山勝東京大学, 生産技術研究所, 助教授 (20134497)
Co-Investigator(Kenkyū-buntansha)	平谷正彦日立製作所, 中央研究所, 主任研究員工藤徹一東京大学, 生産技術研究所, 教授 (90205097)
Keywords	強誘電体 / 半導体 / ビスマス層状構造酸化物 / 交代層構造 / 格子欠陥制御 / 残留分極 / 強誘電性相転移
Research Abstract	強誘電体メモリー用材料として注目を集めているビスマス層状構造強誘電体を対象として、2種類の異なるペロブスカイト層からなる交代層構造をもつ強誘電体の設計と、強誘電性・導電性という異種物性が同時に発現する層状構造体の実現を目指して研究を行った。まず単一のペロブスカイト層をもつビスマス層状構造強誘電体において、不定比性、微量添加物が結晶構造と強誘電物性に及ぼす影響を単結晶および多結晶体を用いて調べた。不定比性により強誘電相転移温度が変化し、原子位置変位の大きさも変わることを明らかにした。さらに、ビスマス欠損と、チタンのバナジウム置換を行ったチタン酸ビスマス多結晶体では、単結晶に匹敵する大きな残留分極値が得られた。これより酸素欠陥量を減少させると分極反転が容易になることが示唆された。次に交代層構造の生じる結晶学的条件および交代層構造による強誘電性の変化を調べた。交代層構造には2種のペロブスカイト層での格子サイズのマッチングが必要なこと、および交代層構造により残留分極が2つの単層体のものより大きな値が生じることが分かった。これは異種層の積層による格子歪みの増大とビスマス層での原子変位が生じたことが原因と考えられる。一方、ペロブスカイト層を導電性とする試みを行い、マンガンイオンを固溶させると添加量とともにp型導電性が増大することを見出した。この導電性ペロブスカイト層と強誘電ペロブスカイト層からなる交代層構造は、不純物相を含むものの合成可能であることを確認した。以上より、ビスマス層状構造強誘電体において分極特性の著しい向上が達成され、また交代層構造の形成と異種物性の融合について設計指針が確立された。

Research Products
(22 results)

All Other

All Publications (22 results)

[Publications] Yuji.Noguchi: "Structural and Dielectric Properties of Intergrowth Bi_4Ti_3O_<12>-SrBi_4Ti_4O_<15> Ceramics"Trans.Mater.Res.Soc.Jap.,. 25・1. 185-188 (2000)
[Publications] Yuji.Noguchi: "Effect of Bi Substitution at the Sr Site on the Ferroelectric Properties of Dense Strontium Bismuth Tantalate Ceramics"J.Appl.Phys.. 88・4. 2146-2148 (2000)
[Publications] Masaru Miyayama: "Electrical Anisotropy in Single Crystals of Bi-layer Structured Ferroelectrics"Ceram.International. 26・5. 529-533 (2000)
[Publications] Sung-Lak Ahn: "Structural and Electrical Characterization of Bi_5Ti_3Fe_<1-x>Mn_xO_<15> System"Mater.Res.Bull.. 35・8. 825-834 (2000)
[Publications] Hiroshi Irie: "Structure dependence of Ferroelectric Properties in Single Crystals of Bismuth Layer-Structured Ferroelectrics"Key Engineering Mater.. 181-182. 27-30 (2000)
[Publications] Yuji.Noguchi: "Analysis of Crystal Structure by the Rietveld Method and Ferroelectric Properties of Sr_<1-x>Bi_<2+x>Ta_2O_9"Key Engineering Mater.. 181-182. 209-212 (2000)
[Publications] Yuji Noguchi: "Ferroelectric Properties of Intergrowth Bi_4Ti_3O_<12>-SrBi_4Ti_4O_<15> Ceramics"Appl.Phys.Lett. 77・22. 3639-3641 (2000)
[Publications] Hiroshi Irie: "Electrical Properties of a Bismuth Layer-structured Ba_2Bi_4Ti_5O_<18> Single Crystal."J.Am.Ceram.Soc.. 83・11. 2699-2704 (2000)
[Publications] Yuji.Noguchi: "Defect Control for Large Remanent Polarization in Bismuth Titanate Ferroelectrics-Doping Effect of Higher-Valent Cations-"Jap.J.Appl.Phys. 39・12B. L1259-1262 (2000)
[Publications] Yuji.Noguchi: "New Intergrowth Bi_2WO_6-Bi_4Ti_3O_<12> Ferroelectrics"J.Ceram.Soc.Jap.. 109・1. 29-32 (2000)
[Publications] Hiroshi Irie: "Enhanced Ferroelectric Properties of V-doped Ba_2Bi_4Ti_5O_<18> Single Crystal,"Jap.J.Appl.Phys.. 40・1. 239-243 (2000)
[Publications] Shi Luo: "Rietvelt Analysis and Dielectric Properties of Bi_2WO_6-Bi_4Ti_3O_<12> Ferroelectric System,"Mater.Res.Bull.. (印刷中). (2001)
[Publications] Hiroshi Irie: "Structure dependence of Ferroelectric Properties of Bismuth Layer-Structured Ferroelectric Single Crystals,"J.Appl.Phys.,. (印刷中). (2001)
[Publications] Yuji,Noguchi: "Direct Evidence of A-site-deficient Strontium Bismuth Tantalate and its Enhanced Ferroelectric Properties,"Phys.Rev.B.. (印刷中). (2001)
[Publications] Hiroshi Irie: "Dielectric and Ferroelectric Properties of SrBi_4Ti_4O_<15> Single Crystal,"Appl.Phys.Lett.. (印刷中). (2001)
[Publications] Yuji.Noguchi: "Large Remanent Polarization of Vanadium-doped Bi_4Ti_3O_<12>,"Appl.Phys.Lett. (印刷中). (2001)
[Publications] Hiroshi Irie: "Crystal structures and Ferroelectric Properties of BaBi4Ti4O15 and V or Ta Substituted Single Crystals"Jap.J.Appl.Phys. (印刷中). (2001)
[Publications] Yuji.Noguchi: "Ferroelectric Properties of Sr_<1-x>Bi_<2+x>Ta_2O_9 Dense Ceramics"IEEE Trans.On Ultrasonics,Ferroelectrics,and Frequency Control. (印刷中). (2001)
[Publications] Yuji,Noguchi: "Ferroelectric Distortion in A-site-deficient Strontium Bismuth Tantalate with Giant Polarization Properties,"Trans.Mater.Res.Soc. (印刷中). (2001)
[Publications] Yuji.Noguchi: "Feroelectric Properties of Ba- and Ta-substituted Bi_3TiTaO_9"Key Engineering Mater.. (印刷中). (2001)
[Publications] Ichiro Miwa: "Effect of Manganese Substitutiion on Electrical Conductivity of Bi_5Ti_3FeO_<15>,"Trans.Mater.Res.Soc.Jpn. (印刷中). (2001)
[Publications] Hiroshi Irie: "Effects of Ta,Nb and V Substitution atTi site on Ferroelectric Properties in BaBi_4Ti_4O_<15> Single Crystals."Key Engineering Mater.. (印刷中). (2001)

2000 Fiscal Year Annual Research Report

強誘電性および導電性の交代層をもつビスマス層状構造酸化物デバイスの開発

Principal Investigator

宮山 勝 東京大学, 生産技術研究所, 助教授 (20134497)

Research Products

[Publications] Yuji.Noguchi: "Structural and Dielectric Properties of Intergrowth Bi_4Ti_3O_<12>-SrBi_4Ti_4O_<15> Ceramics"Trans.Mater.Res.Soc.Jap.,. 25・1. 185-188 (2000)

[Publications] Yuji.Noguchi: "Effect of Bi Substitution at the Sr Site on the Ferroelectric Properties of Dense Strontium Bismuth Tantalate Ceramics"J.Appl.Phys.. 88・4. 2146-2148 (2000)

[Publications] Masaru Miyayama: "Electrical Anisotropy in Single Crystals of Bi-layer Structured Ferroelectrics"Ceram.International. 26・5. 529-533 (2000)

[Publications] Sung-Lak Ahn: "Structural and Electrical Characterization of Bi_5Ti_3Fe_<1-x>Mn_xO_<15> System"Mater.Res.Bull.. 35・8. 825-834 (2000)

[Publications] Hiroshi Irie: "Structure dependence of Ferroelectric Properties in Single Crystals of Bismuth Layer-Structured Ferroelectrics"Key Engineering Mater.. 181-182. 27-30 (2000)

[Publications] Yuji.Noguchi: "Analysis of Crystal Structure by the Rietveld Method and Ferroelectric Properties of Sr_<1-x>Bi_<2+x>Ta_2O_9"Key Engineering Mater.. 181-182. 209-212 (2000)

[Publications] Yuji Noguchi: "Ferroelectric Properties of Intergrowth Bi_4Ti_3O_<12>-SrBi_4Ti_4O_<15> Ceramics"Appl.Phys.Lett. 77・22. 3639-3641 (2000)

[Publications] Hiroshi Irie: "Electrical Properties of a Bismuth Layer-structured Ba_2Bi_4Ti_5O_<18> Single Crystal."J.Am.Ceram.Soc.. 83・11. 2699-2704 (2000)

[Publications] Yuji.Noguchi: "Defect Control for Large Remanent Polarization in Bismuth Titanate Ferroelectrics-Doping Effect of Higher-Valent Cations-"Jap.J.Appl.Phys. 39・12B. L1259-1262 (2000)

[Publications] Yuji.Noguchi: "New Intergrowth Bi_2WO_6-Bi_4Ti_3O_<12> Ferroelectrics"J.Ceram.Soc.Jap.. 109・1. 29-32 (2000)

[Publications] Hiroshi Irie: "Enhanced Ferroelectric Properties of V-doped Ba_2Bi_4Ti_5O_<18> Single Crystal,"Jap.J.Appl.Phys.. 40・1. 239-243 (2000)

[Publications] Shi Luo: "Rietvelt Analysis and Dielectric Properties of Bi_2WO_6-Bi_4Ti_3O_<12> Ferroelectric System,"Mater.Res.Bull.. (印刷中). (2001)

[Publications] Hiroshi Irie: "Structure dependence of Ferroelectric Properties of Bismuth Layer-Structured Ferroelectric Single Crystals,"J.Appl.Phys.,. (印刷中). (2001)

[Publications] Yuji,Noguchi: "Direct Evidence of A-site-deficient Strontium Bismuth Tantalate and its Enhanced Ferroelectric Properties,"Phys.Rev.B.. (印刷中). (2001)

[Publications] Hiroshi Irie: "Dielectric and Ferroelectric Properties of SrBi_4Ti_4O_<15> Single Crystal,"Appl.Phys.Lett.. (印刷中). (2001)

[Publications] Yuji.Noguchi: "Large Remanent Polarization of Vanadium-doped Bi_4Ti_3O_<12>,"Appl.Phys.Lett. (印刷中). (2001)

[Publications] Hiroshi Irie: "Crystal structures and Ferroelectric Properties of BaBi4Ti4O15 and V or Ta Substituted Single Crystals"Jap.J.Appl.Phys. (印刷中). (2001)

[Publications] Yuji.Noguchi: "Ferroelectric Properties of Sr_<1-x>Bi_<2+x>Ta_2O_9 Dense Ceramics"IEEE Trans.On Ultrasonics,Ferroelectrics,and Frequency Control. (印刷中). (2001)

[Publications] Yuji,Noguchi: "Ferroelectric Distortion in A-site-deficient Strontium Bismuth Tantalate with Giant Polarization Properties,"Trans.Mater.Res.Soc. (印刷中). (2001)

[Publications] Yuji.Noguchi: "Feroelectric Properties of Ba- and Ta-substituted Bi_3TiTaO_9"Key Engineering Mater.. (印刷中). (2001)

[Publications] Ichiro Miwa: "Effect of Manganese Substitutiion on Electrical Conductivity of Bi_5Ti_3FeO_<15>,"Trans.Mater.Res.Soc.Jpn. (印刷中). (2001)

[Publications] Hiroshi Irie: "Effects of Ta,Nb and V Substitution atTi site on Ferroelectric Properties in BaBi_4Ti_4O_<15> Single Crystals."Key Engineering Mater.. (印刷中). (2001)

宮山勝東京大学, 生産技術研究所, 助教授 (20134497)