| Project/Area Number |
15560006
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied materials science/Crystal engineering
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| Research Institution | Mie University |
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Principal Investigator |
ENDO Tamio Mie University, Graduate School of Bioresources, Graduate School of Engineering, Professor, 大学院工学研究科, 教授 (80115691)
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| Project Period (FY) |
2003 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2006: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2005: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2004: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2003: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | Tunable microwave filters / HTS YBCO thin films / Ferromagnetic LBMO. LSMO films / Ion Beam Sputtering / YBCO / LBMO double layers / Microwave absorption / Degradations under double-layers depositions / Superlattice LCMO / ナノ材料 / 超伝導材料 / 積層薄膜 / 複合材料・物性 / 強相関電子系 / LSMO / YBCO, LBMO / YBCO積層膜 / 強磁性LSMO, LBMO薄膜 / ステップ・テラス構造 / 薄膜の劣化 / イオンビームスパッタ法 / ZnO Thin Films / a / c配向YBCO薄膜作成 / c配向機構と制御 / PLDc配向YBCO薄膜作成 / c薄膜のマイクロ波吸収 / 磁束運動と粘性 / 磁束運動の異方性 / LBMO薄膜 / LBMO / YBCO積層膜の作成 / マイクロ波フィルター / YBCO薄膜 / a-c配向 / 基板温度 / 酸素分圧 / 酸素分子・プラズマ / 薄膜結晶性 / LBMO積層膜 |
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| Research Abstract |
Double layers of Ferromagnetic/Hi-Tc-Superconductors (HTS) can be used for tunable microwave filters at base stations of mobile phone system. Permeability of Ferro-layer is modified by magnetic field, leading to modification of microwave propagation on HTS-layer. It is necessary to obtain single-layers and double-layers which complete such functions. Further, it is important to elucidate microwave absorption (MA) in HTS under magnetic field (H), problems of deteriorations under the double layers depositions and elapsed-degradations of thin films in application periods. In this project, we studied [1] thin film growths of Ferro-LSMO and-LBMO single layers, [2] double layer depositions of LSMO/YBCO and LBMO/YBCO (YBCO: HTS-layer), and their degradations, [3] microwave absorptions in HTS-YBCO and Superlattices under magnetic field.
YBCO thin films were deposited on Mg0 and LAO substrates by Ion Beam Sputtering (IBS) with oxygen plasma supply. We succeeded to grow them at ultra-low temperat
… More
ures and obtained extremely smooth films. We could control a/c-orientation growths completely and elucidated a mechanism of a/c-orientations <surface migration>. Fine crystalline LSMO and LBMO thin films could be grown at ultra-low temperatures. LSMO showed 2D step-terrace growth mode. LSMO over-layers could be grown on a-YBCO under-layers but a part of a-YBCO was changed into c-YBCO. High quality YBCO over-layers could be grown on LBMO under-layers. During the double-layer depositions, the crystallinity of under-LBMO was not degraded but the double-layer surface was much roughened. The surface was very smooth when LBMO was deposited on YBCO layers but under-YBCO was degraded during the double-layer depositions. The crystallinity showed large elapsed-degradations for a few years for a-YBCO/Mg0 but not for a-YBCO/LAO. It was known that the degradation is concerned with lattice matching.
High Tc (86 K) a-YBCO and c-YBCO were fabricated by PLD, and their MA was investigated under H. MA was larger for c-YBCO than for a-YBCO. MA was smaller for H//a than for H//c then it was clarified that a-YBCO is more useful for the double-layered tunable microwave filters. It was elucidated by theoretical analysis that an <excess screening current mechanism> is a major factor for MA. We measured MA on LCMO/YBCO superlattice, and found a quite important fact that MA is large for H perpendicular to the plane but negligible small for H parallel to the plane. Thus we could propose that we can minimize the microwave absorption in HTS-layers for the parallel magnetic field when the Ferro/HTS double-layers (superlattices) will be used for tunable microwave filters in the near future. Less
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