（開催中止）第200回フロンティア材料研究所学術講演会（Prof. Wei-tin Chen）
| 開催日時 | 2025年07月22日 14:00 –15:00 |
|---|---|
| 開催場所 | 東京科学大学すずかけ台キャンパス J1-809（地図㉘） |
| 主催 | 東京科学大学 総合研究院 フロンティア材料研究所 |
| 連絡先 | 東研究室 東正樹（5315） |
| 備考 | 本講演会は都合により開催を中止させていただきます。（2025年7月22日追記） |
プログラム等
講師： Professor Wei-tin Chen （National Taiwan University）
演題： "Crystal and magnetic structure of mercury quadruple perovskite"
概要：
AMn7O12 manganite belongs AA’3B4O12 quadruple perovskite family, and a novel quadruple perovskite HgMn7O12 (HMO) was prepared by high pressure high temperature (HPHT) synthesis techniques. HMO exhibit intriguing phase transitions owing to rich charge and orbital orderings, and multiferroic property at low temperature. [1] In addition to the charge ordering (CO) phase transition observed at its analogue cousin CaMn7O12, HMO experiences a further symmetry-lowering phase transition, which is most likely owing to the contribution from the mercury cation. In order to further investigate the peculiar structural behavior and the competition between charge and orbital ordering, a series of isovalent calcium and aliovalent sodium and lanthanum doped samples were prepared. The electronic phase separation, and pronounced competition between charge and orbital ordering modes were observed in sodium doped HMO. [2] The evolution of the crystal and magnetic structure of the solid solution will be discussed in this talk.
[1] Chen, W.-T. et. al., Physical Review B, 97, 144102 (2018)
[2] Ben R. M. Tragheim et. al., Physical Review B, 110, 245123 (2024)
