四角形BaCoO:一个Co4+铁磁Mott绝缘体
Mingyu Xu1, Haozhe Wang1, Krishna Prasad Koirala2
1Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States.
The journal of physical chemistry. C, Nanomaterials and interfaces
|November 12, 2025
概括
研究人员使用高压和高温稳定了氧化 (BCT-BaCoO3) 的转移稳定体中心四角形相. 这个阶段表现出铁磁排序和绝缘行为,为稳定高压材料提供了洞察力.
科学领域:
- 材料科学 材料科学 材料科学
- 固态物理 固态物理
- 晶体学 晶体学是指结晶学.
背景情况:
- 已知氧化氧化 (BaCoO3) 在不同的条件下表现出各种相位.
- 稳定复杂氧化物的转稳定相对于发现具有独特性质的新材料至关重要.
研究的目的:
- 为了稳定BaCoO3.3的转移性身体中心四角形 (BCT) 阶段.
- 描述稳定BCT-BaCoO3阶段的结构,电子和磁性特性.
- 探索在环境条件下保存高压相的方法.
主要方法:
- 高压 (15GPa) 和高温 (1200°C) 合成,使用混合物前体.
- 粉末X射线衍射和高分辨率STEM用于结构分析.
- 进行X射线光电子光谱,磁化,热容量和电阻测量,以进行属性表征.
- 密度函数理论 (DFT) 和DFT+动态平均场理论 (DMFT) 的计算.
主要成果:
- 用EuTiO3型结构 (空间组I4/mcm) 稳定BCT-BaCoO3阶段.
- 主要的CO4+氧化状态得到确认,没有可检测到的氧气空缺.
- 在TC~107K观察到铁磁排序,这是BCT-BaCoO3阶段的特征.
- 具有弱磁阻的绝缘行为,归因于轨道选择性过渡.
- 超稳定阶段在环境压力下不能保持纯粹的形式.
结论:
- 在特定的高压/高温条件下,可稳定转移性BCT-BaCoO3阶段.
- 将BCT-BaCoO3相嵌入无序混合物中,可以使其在环境压力下稳定.
- 这种方法为发现和保存其他高压相提供了潜在的途径.
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