Elucidation of mechanism and verification of multipole origin for novel physical properties in rare-earth sulfides aimed at exploring new materials for the next generation

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K05238
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 29010:Applied physical properties-related
• Research Institution: Muroran Institute of Technology
• Principal Investigator: Ebisu Shuji 室蘭工業大学, 大学院工学研究科, 教授 (10250523)
• Co-Investigator(Kenkyū-buntansha): 宮崎 正範 室蘭工業大学, 大学院工学研究科, 助教 (30634357)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 希土類硫化物 / 単結晶育成 / 異常磁気伝導 / 電気抵抗率異常増減 / 巨大物性応答 / 磁化容易軸交換 / 磁場中試料回転 / 一軸圧

Outline of Final Research Achievements

In order to elucidate the mechanism of the novel physical properties, especially the anomalous enhancement/restoration of electrical resistivity in the narrow temperature range near the magnetic transition temperature, for single crystals of rare earth sesquisulfides α-R2S3, μSR experiments using microprobe and macroscopic physical property measurements were carried out. We conclude that the phenomenon is caused by a large magnetic fluctuation due to the short-range ordering of magnetic moments in the temperature range of T > TC1 for α-Sm2S3 and T > TN2 for α-Dy2S3. In addition, we consider that there are multiple metastable ground states of rare-earth ions in the crystalline field of this compound, and the coexistence of these states leads to a strange crossing of the easy magnetization axes, and the transitions between these states cause gigantic physical property responses.

Free Research Field

物性物理分野

Academic Significance and Societal Importance of the Research Achievements

狭い温度範囲で6桁にも及ぶ電気抵抗率の急増・急減というのは希有な現象であり、その機構を解明することはそれ自体が学術的に意義深く、また新しいタイプの巨大物性応答を示す化合物群を探索する手掛かりにもなり得る。外場に対して巨大な物性応答が得られれば、その物質は高効率・省エネルギー・低環境負荷で、ある機能を発揮する新材料となり、高機能電子デバイスへの展開が期待される。