在矿Mott系统中实现对电子相关度的调制,通过调A位共价性
Jingxin Gao1, Yusong Zhao1, Hao Zhang1
1School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, China.
Small (Weinheim an der Bergstrasse, Germany)
|January 15, 2026
概括
矿尼基酸盐中的电子相关性 (U) 是其独特性质的关键. 研究人员通过添加Bi来调整U,显著改善金属到绝缘体的过渡和增强电阻开关.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 材料科学 材料科学 材料科学
- 固态化学 固态化学
背景情况:
- 在d轨道矿Mott系统中的电子相关性 (U) 驱动了金属到绝缘体过渡 (MIT),高TC超导和多铁素等功能.
- 在这些材料中调节电子相关性 (U) 仍然是一个挑战.
研究的目的:
- 开发一种策略来调整相关的矿尼基酸盐 (RENiO3) 中的电子相关性 (U).
- 通过Bi-substitutions对U和材料属性的RE-site共价性操纵的影响进行调查.
主要方法:
- 在RENiO3的RE-site中引入了部分Bi-substitution以操纵RE-site共价性.
- 基于同步光子的X射线吸收光谱仪被用来探测电子结构的变化.
- 使用第一原则计算来支持实验发现,并了解潜在的机制.
主要成果:
- 双替代物增加了Bi-6s和O-2p之间的共价,扩大了Ni-3d占用率,并增加了U的2-3倍.
- 基态带间隙 (Eg) 和电阻率得到了有效的提高,在可调节的临界温度 (TMIT) 上,电阻开关的增强率高达40倍,从75-400 K.
- 由于较大的离子半径,双替换降低了TMIT,表明电荷转移间隙,而不是U,决定了MIT的相稳定性.
结论:
- 通过A位共价的调节电子相关性 (U) 为优化相关矿的功能提供了一条新的途径.
- 这项研究成功地证明了对金属到绝缘体过渡的增强控制以及尼基酸盐中的电阻切换特性.
- 电子相关性 (U) 主要影响基本状态属性,而电荷转移差距决定相位稳定性和过渡温度.
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