ルテニウム酸化物の磁性と輸送特性

氧化钌的磁性和输运性质

• 批准号: 01F00774
• 负责人: 前野 悦輝
• 金额: $ 1.15万
• 依托单位: Kyoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for JSPS Fellows
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-01F00774/
• 关键词: ルテニウム酸化物; メタ磁性転移; 量子臨界現象; Sr_3Ru_2O_7; 強相関電子系; 酸化物単結晶育成; 量子振動; フェルミ面

高温超伝導や巨大磁気抵抗などの著しい物理現象は、電子同士が強く相互作用する物質(強相関電子系)の特徴である。その電子状態の統一的理解を深めることは、現代の固体物理学における最重要テーマのひとつである。ルテニウム酸化物では、スピン三重項超伝導やモット転移など強相関電子系に特徴的な物理現象が見られる。本研究の目的は,その単結晶の純良化をさらに進め、磁性・輸送特性の精密測定を通して、強相関電子系の酸化物磁性の理解を深めることにある。本研究ではメタ磁性転移が量子臨界現象として扱えるという新視点を提唱し、特にSr_3Ru_2O_7について集中的に研究して以下の成果を収めた。1.純良単結晶育成の新しい方法の開発赤外線加熱単結晶炉は酸化物単結晶の育成に広く用いられるが、融解物の蒸気圧が高い場合は、元素欠損等のために純量化が困難になる。本研究では蒸発量を秤量することで育成条件を最適化する系統的な方法を開発した。これをSr_3Ru_2O_7に適用した結果、残留抵抗率が従来の5分の1以下の純良大型単結晶を再現性よく育成できるようになった。2.メタ磁性量子臨界点近傍での多重1次相転移現象の観測ルテニウム酸化物Sr_3Ru_2O_7のメタ磁性量子臨界現象の研究を進めた。磁場を擬2次元面に垂直に印加した場合、メタ磁性1次相転移の終点温度が絶対零度に近づき、量子臨界現象が現れる。本研究では30ミリケルビンまでの低温での交流磁化率、磁化、電気抵抗率の測定を行い、純良試料では1ケルビン以下に新たな多重1次相転移が現れることを明らかにした。この1次相転移線で挟まれた領域では、低温での電気抵抗増大などの新奇現象が見られた。3.メタ磁性転移に伴うフェルミ面の再構成の観測Sr_3Ru_2O_7単結晶の純良化を進めた結果、磁化率に量子振動が現れるようになり、電子構造(フェルミ面)を決定することができた。そしてメタ磁性量子臨界現象にともなって、フェルミ面の再構築が起こることを明らかにした。

The high-temperature superconducting giant magnets resist the physical phenomena, and the electrons and electrons strongly interact with each other (the strong phase electronic system). In order to understand the integrity of electronic systems, it is important to understand the most important aspects of solid-state physics. The purpose of this paper is to investigate the physical characteristics of the phase electrical system due to the presence of acid compounds and chemical compounds. The purpose of this study is to improve the experimental results, to improve the precision measurement of magnetic transport properties, and to strengthen the magnetic properties of acidified materials in the electrical system. In this study, the magnetism shifts the quantum boundary, such as the new spot singing, the special Sr_3Ru_2O_7 research focus on the following results. 1. A new method for the development of a new method is to develop a new method for the development of a new method. In this study, we developed a method to optimize the system of steaming, weighing, weighing and developing conditions. The results of the test results and the rate of residual resistance were used to determine the accuracy of the results and the residual resistance rate of Sr _ 3Ru_2O_7. The results of the test results and the residual resistance rate were used to improve the large-scale results below 5 points. two。 Near the boundary point of magnetic quantum, the image of multiple first phase shift, the image of acidified Sr_3Ru_2O_7, the boundary of magnetic quantum, the image of multiple phase shift, the image of magnetic quantum boundary, the image of magnetic quantum boundary, the image of magnetic quantum boundary and the image of magnetic quantum boundary have been improved. The magnetic field has two dimensional planes, vertical Inca planes, magnetic phase shifts, point temperatures, zero degrees, and quantum boundaries. The purpose of this study is to determine the AC magnetic susceptibility, magnetization and electrical impedance of the cryogenic temperature system at low temperature. in this study, the AC magnetic susceptibility, magnetization and electrical impedance of the cryogenic temperature range are measured. The first phase shift is a threat to the field and cryogenic power plants to resist the novelty of high-speed electricity. 3. The magnetic transfer is accompanied by the reconfiguration of the surface layer of the Sr_3Ru_2O_7, and the results of the improved analysis, the magnetic susceptibility, the quantum vibration of the magnetic susceptibility, and the electron generation (the temperature field) determine the effect of the magnetic field. The boundary of the magnetic quantum system is similar to that of the magnetic quantum, which is similar to the magnetic quantum boundary.

项目成果

R.S.Perry: "The Out-of-Plane Magneto-Resistivity of Sr_3Ru_2O_7"Physica B. 329-333. 904-905 (2003)

R.S.Perry：“Sr_3Ru_2O_7 的面外磁阻”Physica B. 329-333。

L.Capogna: "Metamagnetic Transition and Low-Energy Spin Density Fluctuations in Sr_3Ru_2O_7"Lecture Notes in Physics. 603. 290-302 (2002)

L.Capogna：“Sr_3Ru_2O_7 中的变磁跃迁和低能自旋密度涨落”物理学讲义。

M.Chiao: "Effect of Pressure on Metamagnetic Sr_3Ru_2O_7"Physica B. 312. 698-699 (2002)

M.Chiao：“压力对变磁Sr_3Ru_2O_7的影响”Physica B. 312. 698-699 (2002)

R.S.Perry: "Multiple First-Order Metamagnetic Transitions and Quantum Oscillations in Ultra-pure Sr_3Ru_2O_7"Physical Review Letters. (accepted for publication). (2004)

R.S.Perry：“超纯 Sr_3Ru_2O_7 中的多重一阶变磁跃迁和量子振荡”物理评论快报。

R.S.Perry: "Systematic Approach to the Growth of High-Quality Single-Crystals of Sr_3Ru_2O_7"Journal of Crystal Growth. (accepted for publication). (2004)

R.S.Perry：“高质量 Sr_3Ru_2O_7 单晶生长的系统方法”晶体生长杂志。