Controlling the magnetism of intermediate-valence Tsai-type clusters

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K03715
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 13030:Magnetism, superconductivity and strongly correlated systems-related
• Research Institution: Nagoya University
• Principal Investigator: Imura Keiichiro 名古屋大学, 理学研究科, 助教 (10444374)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 価数揺動 / 準結晶 / 近似結晶 / 発光分光

Outline of Final Research Achievements

In this study, we have investigated the electronic structure and magnetic properties of quasicrystals and approximant crystals whose constituents are atomic clusters called Tsai-type clusters. By changing the size of Tsai-type clusters by applying external pressure or elemental substitutions, we have revealed a characteristic lattice parameter at which the mean-valence of the rare-earth ions in the cluster changes abruptly. We also found that the magnetic susceptibility diverges power-divergently with temperature at the critical lattice constant. This result indicates that there is a strong relationship between the fluctuation of the mean- valence and the unique magnetic properties.

Free Research Field

強相関電子物性

Academic Significance and Societal Importance of the Research Achievements

本研究は、強相関電子系の知見をベースに、希土類イオンを含む準結晶・近似結晶における電子状態と磁気特性を調べることで、価数揺らぎと量子臨界現象の関連について明らかにしたものである。その結果、準結晶が外部パラメータに対して強固な量子臨界性を示す事を明らかにした。本成果は、従来の周期結晶における考え方とは異なる概念を構築するものであり、新たな研究領域を確立できる学術的意義を持つ。