研究課題
基盤研究(C)
強磁性/高温超伝導・積層薄膜は携帯電話中継基地局で使用される可変マイクロ波フィルターへの応用が期待されている。磁場印加によって強磁性層の透磁率が変調され、超伝導層を伝播するマイクロ波伝播モードが変調できるからである。その実現には、それぞれの役割を担える単層膜と積層膜の作成が必要である。また高温超伝導体の磁場下でのマイクロ波吸収、積層膜作成中の下層膜(強磁性層と高温超伝導層)の劣化の問題、および応用上その経時劣化が重要な研究課題となる。本研究では強磁性(LSMO, LBMO)単層膜の作成および積層膜LSMO/YBCOとLBMO/YBCO(YBCO:高温超伝導層)の作成と劣化について研究した。またYBCO超伝導薄膜と超格子薄膜の磁場下でのマイクロ波吸収を調べた。酸素プラズマ供給型イオンビーム・スパッタ(IBS)装置でMgOとLAO基板上にYBCO薄膜を作成した。低温成長に成功し、究極の表面平滑膜を得た。a軸とc軸配向成長を制御し、その機構(表面マイグレーション)を解明した。LBMOとLSMO薄膜を作成し、優れたLBMO薄膜結晶が低温成長できた。LSMO薄膜は2次元ステップ・テラス成長を示す。a-YBCO下層上にLSMO上層を積層できたが、a-YBCOの1部がc-YBCOに転移した。高品質のYBCO層をLBMO層上に積層できた。積層中に下層LBMOの結晶性は劣化しないが、2層膜の表面粗れが増強した。LBMO層をYBCO層上に積層すると非常に平滑であるが、下層YBCOが劣化した。MgO基板上のa-YBCOは大きな経時劣化を示したが、LAO基板上では小さかった。劣化が格子整合と関連していることを示した。PLD法で高転移温度(86K)のa-YBCOとc-YBCO薄膜を作成し、磁場(H)下でのマイクロ波吸収(MA)を測定した。c-YBCOのMAはa-YBCOに比べて大きい。MAはH//cよりもH//aの方が小さいのでa-YBCOは積層可変マイクロ波フィルターに有利であることがわかった。理論解析の結果<過剰遮蔽電流機構>が重要であることを明らかにした。LCMO/YBCO超格子薄膜のMAを測定した結果、磁場を膜面に垂直に印加すると大きなMAを示すが、平行に印加するとほとんどゼロであることを見出した。可変マイクロ波フィルターに適用するとき、磁場を平行に掛ければマイクロ波の損失を小さく抑えることができることを提案できた。
すべて 2007 2006 2005 2004 2003
すべて 雑誌論文 (159件) 図書 (2件)
International Journal of Nanoscience Vol.5 No.4-5
ページ: 511-515
Progress in Electromagnetics Research Symposium 2006 (Cambridge, USA), (06/3/29)
Beijing International Materials Week -International Conference on Superconducting Materials 2006 (Beijing, China), (06/6/27)
International Conference on Composites/Nano Engineering 2006 (Boulder, USA), (06/7/7)
International Conference on Composites/Nano Engineering 2006 (Boulder, USA), (06/7/3)
Progress in Electromagnetics Research Symposium 2006 (Tokyo, Japan), (06/8/2-5)
International Colloquium on Magnetic Films and Surfaces 2006 (Sendai, Japan), (06/8/15-18)
Mie University Open Seminar [Oxides and Nano-ferromagnetism(1)] (Tsu, Japan), (06/8/26)
Mie University Open Seminar [Oxides and Nano-ferromagnetism(2)] (Tsu, Japan), (06/8/31)
IUMRS - International Conference in Asia 2006 (Jeju, Korea), (06/9/11)
Effects of Substrate Surface Exposure to Oxygen-Plasma on a-c Orientation Growth of YBCO : Verification of Surface Migration Mechanism <Invited Talk>
International Conference on Recent Trends in Nanoscience and Technology 2006 (Kolkata, India), (06/12/7-9)
Progress In Electromagnetics Research Symposium, (2006/3/26-29), Cambridge, USA, <Invited Lecture>
Beijing International Materials Week - International Conference on Superconducting Materials 2006 (Beijing, China), (06/6/27)
International Conference on Composites/Nano Engineering 2006 (Boulder, USA)
Progress in Electromagnetics Research Symposium 2006 (Tokyo, Japan)
International Colloquium on Magnetic Films and Surfaces 2006 (Sendai, Japan)
Mie University Open Seminar [ Oxides and Nano-ferromagnetism(1) ] (Tsu, Japan)
Mie University Open Seminar [ Oxides and Nano-ferromagnetism(2) ] (Tsu, Japan)
IUMRS-3International Conference in Asia 2006 (Jeju, Korea)
International Conference on Solid Films and Surfaces 2006 (Bariloche, Argentina)
International Conference on Recent Trends in Nanoscience and Technology 2006 (Kolkata, India)
Proc. PIERS-05 (Hangzhou, China)
ページ: 22-26
Proc. ICCE-12 (Tenerife, Spain)
Proc. ICMAT-05 (Singapore)
Proc. Tri-University International Joint Seminar and Symposium, (Zhenjiang, China)
Trans. Mat. Res. Soc. Jpn. 30(3)
ページ: 761-764
International Conference on Materials for Advanced Technologies / International Conference on Advanced Materials, (2005/7/3-8),Singapore, <Invited Lecture>
International Conference on Materials for Advanced Technologies / International Conference on Advanced Materials, (2005/7/3-8),Singapore
International Conference on Materials for Advanced Technologies / International Conference on Advanced Materials, (2005/7/3-8), Singapore
International Conference on Composites/Nano Engineering, (2005/8/1-6), Tenerife, Spain,<Invited Lecture>
Progress In Electromagnetics Research Symposium, (2005/8/22-26), Hangzhou, China, <Invited Lecture>
Tri-University International Joint Seminar and Symposium, (2005/10/16-21), Zhenjiang, China, <Invited Lecture>
International Conference on Optoelectronic Materials and Thin Films for Advanced Technology, (2005/10/24-27), Cochin, India, <Invited Lecture>
International Symposium on Surface Science and Nanotechnology, (2005/11/14-17), Omiya,Japan
Materials Research Society Fall Meeting, (2005/11/28-12/2), Boston, USA, <Invited Lecture>
International Workshop on the Physics of Semiconductor Devices, (2005/12/13-17), New Delhi, India, <Invited Plenary Lecture>
Proc. PIERS-05 (Hangzhou, China) 22-26
International Conference on Materials for Advanced Technologies / International Conference on Advanced Materials, Singapore, <Invited Lecture>
International Conference on Materials for Advanced Technologies / International Conference on Advanced Materials, Singapore
International Conference on Composites/Nano Engineering, Tenerife, Spain, <Invited Lecture>
Progress In Electromagnetics Research Symposium, Hangzhou, China, <Invited Lecture>
Tri-University International Joint Seminar and Symposium, Zhenjiang, China, <Invited Lecture>
International Conference on Optoelectronic Materials and Thin Films for Advanced Technology, Cochin, India, <Invited Lecture>
International Symposium on Surface Science and Nanotechnology, (2005/11/14-17), Omiya, Japan
Proc. ICCE-11 (South Carolina, USA)
ページ: 157-158
Proc. APMC (New Delhi, India)
ページ: 790-793
ページ: 698-701
Trans. Mat. Res. Soc. Jpn. 29(4)
ページ: 1431-1436
Proc. Int. Workshop on Crystal Growth and Characterization of Technologically Important Materials (Chennai, India)
ページ: 89-111
International Workshop on Crystal Growth and Characterization of Technologically Important Materials, (2004/2/24-28), Chennai, India,<Invited>
Taiwan International Conference on Superconductivity and the 7 th Workshop on Low Temperature Physics, (2004/7/5-9), Penghu, Taiwan, <Invited>
International Conference on Composites/Nano Engineering, (2004/8/8-14), Hilton Head Island, USA, <Invited>
WSEAS, (2004/8/16), Athen, Greece, <Invited>
NATO Advanced Research Workshop on Vortex Dynamics in Superconductors and Other Complex System, (2004/9/13-17), Yalta, Ukraine, <Invited>
International Workshop on Inelastic Ion-Surface Collisions, (2004/10/17-22),Ise-Shima, Japan
Asia-Pacific EPR/ESR Symposium 2004,(2004/11/22-25), Bangalore, India, <Invited>
MRS Fall Meeting 2004, (2004/12/29-12/2),Boston, USA, <Invited>
Asia-Pacific Microwave Conference,(2004/12/15-18), New Delhi, India, <Invited>
Asia-Pacific Microwave Conference (2004/12/15-18), New Delhi, India, <Invited>
Proc. ICCE-11 (South Carolina, USA) 157-158
Proc. APMC (New Delhi, India) 790-793
Proc. APMC (New Delhi, India) 698-701
Proc. Int. Workshop on Crystal Growth and Characterization of Technologically Important Materials (Chennai, India) 89-111
International Workshop on Crystal Growth and Characterization of Technologically Important Materials, Chennai, India, <Invited Lecture>
International Workshop on Crystal Growth and Characterization of Technologically Important Materials, Chennai, India, <Invited>
Taiwan International Conference on Superconductivity and the 7 th Workshop on Low Temperature Physics, Penghu, Taiwan, <Invited>
International Conference on Composites/Nano Engineering, Hilton Head Island, USA, <Invited>
WSEAS, Athen, Greece, <Invited>
NATO Advanced Research Workshop on Vortex Dynamics in Superconductors and Other Complex System, Yalta, Ukraine, <Invited>
International Workshop on Inelastic Ion-Surface Collisions, Ise-Shima, Japan
Asia-Pacific EPR/ESR Symposium 2004, Bangalore, India, <Invited>
MRS Fall Meeting 2004, Boston, USA, <Invited>
Asia-Pacific Microwave Conference, New Delhi, India, <Invited>
Proc. 10^th Int. Conf. on Composites/Nano Engineering (New Orleans, 2003)
ページ: 795-796
ページ: 171-172
Proc. Ninth National Seminar on Crystal Growth, (Chennai, 2003)
ページ: 2-3
Physica B 329-333
ページ: 791-793
ページ: 794-796
Physica C 388-389
ページ: 687-688
Supercond. Sci. Technol 16
ページ: 110-119
Physica C 392-396
ページ: 463-467
Trans. Mat. Res. Soc. Jpn 28-4
ページ: 1117-1120
ページ: 1121-1124
ページ: 1125-1128
New Materials (Proc. Asia Academic Seminar 2001)
ページ: 205-223
International Conference on Composites/Nano Engineering, (2003/7/20-26), New Orleans, USA, <Invited>
International Conference on Composites/Nano Engineering, (2003/7/20-26), New Orleans, USA
The 8th IUMRS International Conference on Advanced Materials, (2003/10/8-13), Yokohama,Japan, <Invited>
The 8th IUMRS International Conference on Advanced Materials, (2003/10/8-13), Yokohama,Japan
The 8th IUMRS International Conference on Advanced Materials, (2003/10/8-13), Yokohama, Japan
Satellite Seminar on Variety of Oxide Materials and Properties, (2003/10/14), Tsukuba, Japan,<Invited>
Twelfth International Workshop on The Physics of Semiconductor Devices, (2003/12/16-20),Chennai, India, <Invited>
International Workshop on Crystal Growth and Characterization of Technologically Important Materials, (2004/2/24-28), Chennai, India,<Invited Lecture>
Supercond. Sci. Technol. 16
Trans. Mat. Res. Soc. Jpn 0
Proc. 10^<th> Int. Conf. on Composites/Nano Engineering (New Orleans, 2003) 795-796
Proc. 10^<th> Int. Conf. on Composites/Nano Engineering (New Orleans, 2003) 171-172
Proc. Ninth National Seminar on Crystal Growth, (Chennai, 2003) 2-3
International Conference on Composites/Nano Engineering, New Orleans, USA, <Invited>
International Conference on Composites/Nano Engineering, New Orleans, USA
The 8th IUMRS International Conference on Advanced Materials, Yokohama, Japan, <Invited>
The 8th IUMRS International Conference on Advanced Materials, Yokohama, Japan
Satellite Seminar on Variety of Oxide Materials and Properties, Tsukuba, Japan, <Invited>
Twelfth International Workshop on The Physics of Semiconductor Devices, Chennai, India, <Invited>
