Odd-parity multipole order and unusual ordering in Kondo semiconductor

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K05546
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Condensed matter physics II
• Research Institution: Toyama Prefectural University
• Principal Investigator: Tanida Hiroshi 富山県立大学, 工学部, 准教授 (00452615)
• Co-Investigator(Kenkyū-buntansha): 西岡 孝 高知大学, 教育研究部自然科学系理工学部門, 教授 (10218117)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 強相関電子系

Outline of Final Research Achievements

Unusual antiferromagnetic (AFM) Kondo semiconductor CeT2Al10 system (T=Fe,Ru,Os) were investigated for pressure effect and substitution effect. We obtained information on the relation between the hybridization gap typical for the Kondo semiconductor and the unusual AFM order. The origin of the magnetic excitation found at the early stage of this study remains unsolved, but progress has been obtained by neutron experiments.
Metallic antiferromagnet CeCoSi without local space inversion symmetry was also examined from an "odd-parity" multipole ordering point of view. We succeeded in synthsizing single crystals of CeCoSi for the first time, and proposed the possibility of "odd-parity" multipole order.

Free Research Field

強相関電子系

Academic Significance and Societal Importance of the Research Achievements

近藤半導体で磁気秩序を示す化合物はまず存在しないと考えられるが、予想に反し、「セリウム―遷移金属－アルミニウム」化合物は、異常に高い温度で磁気秩序を示す。本研究成果により、新しい磁気材料、半導体材料、などの開発に繋がる可能性がある。
「セリウム―遷移金属―シリサイド」については、初めて単結晶合成に成功し、非従来型の秩序相である「奇パリティ多極子秩序相」における研究のスタート地点を築いた。