(Canceled) 200th MSL Lecture (Prof. Wei-tin Chen)
| Date/Time | 2025/07/22 14:00 –15:00 |
|---|---|
| Place | J1-809, Suzukakedai campus (No.28) |
| Organizer | Materials and Structures Laboratory, Institute of Integrated Research, Institute of Science Tokyo |
| Contact | Prof. Masaki Azuma |
| Language | English |
| Remarks | This lecture has been cancelled. (Added on July 22, 2025) |
Subject & Detail
Speaker: Professor Wei-tin Chen (National Taiwan University)
Lecture theme: "Crystal and magnetic structure of mercury quadruple perovskite"
Abstract:
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)
