Insulator-to-metal transition and ferromagnetic properties of alkali-metal s-electron system in regular nanospaces of zeolites

2016 Fiscal Year Final Research Report

• Project/Area Number: 24244059
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Condensed matter physics II
• Research Institution: Osaka University
• Principal Investigator: Nozue Yasuo 大阪大学, 理学研究科, 教授 (60125630)
• Co-Investigator(Kenkyū-buntansha): 萩原 政幸 大阪大学, 理学(系)研究科(研究院), 教授 (10221491) ; 中野 岳仁 大阪大学, 理学(系)研究科(研究院), 助教 (50362611) ; 五十嵐 睦夫 群馬工業高等専門学校, その他部局等, 教授 (60259819)
• Project Period (FY): 2012-04-01 – 2017-03-31
• Keywords: 絶縁体金属転移 / 磁性 / アルカリ金属 / クラスター / ゼオライト / 電子相関 / 電子格子相互作用 / ポーラロン

Outline of Final Research Achievements

The s-electrons of alkali metals are assigned to the ideal free-electron system, but they display novel properties in the regular nanospaces of zeolite crystals. These s-electrons are quantized in the nanoclusters in zeolite cages, and have an electron correlation due to the mutual Coulomb repulsion and also the electron-phonon interaction due to the displacement of alkali cations. As the results, s-electrons display ferromagnetic properties and insulator-to-metal transition depending on the loading density of alkali metals. These properties vary widely with the kind of alkali metals and the structure type of zeolites as well. A huge spin-orbit interaction is observed in the degenerate orbitals of clusters due to the lack of inversion symmetry at the internal surface of clusters. These novel properties can be understood systematically through this research.

Free Research Field

物性物理学