在变磁候选物Mn5Si3中观察异常的Nernst效应
Antonín Badura1,2, Warlley H Campos3,4, Venkata K Bharadwaj4
1Institute of Physics, Czech Academy of Sciences, Prague, Czechia. badura@fzu.cz.
Nature communications
|August 2, 2025
概括
替代磁铁是一种新型的磁性材料,即使没有净磁化,也可以实现异常的Nernst效应. 长轴Mn5Si3薄膜表现出这种效应,为先进的热电学铺平了道路.
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
- 固态物理 固态物理
背景情况:
- 异常的Nernst效应 (ANE) 从磁性材料中的热梯度产生横向电压.
- 传统上被排除在补偿对直线磁体中,现在可以在变磁体中使用ANE.
- 替代磁铁具有独特的对称性特性,允许ANE尽管零净磁化.
研究的目的:
- 调查在表层Mn5Si3薄膜中的异常Nernst效应.
- 证明Mn5Si3中的反磁性及其在使ANE成为可能中的作用.
- 探索热电学和自旋热力电子学的潜在应用.
主要方法:
- 在基板上的Mn5Si3薄膜的表面增长.
- 对异常的Nernst效应进行实验测量.
- 密度函数理论 (DFT) 计算动量解析的异常Nernst导电性.
主要成果:
- 在0磁场下,Epitaxial Mn5Si3薄膜呈现出自发的异常Nernst效应.
- 观察到自发异常的Nernst系数为0.26μV/K,电导率为0.22A/K·m.
- DFT计算证实了变磁性,并确定了来自贝里曲率,伪节点表面和梯子过渡的贡献.
结论:
- 长轴Mn5Si3薄膜已被证实是表现出异常Nernst效应的替代磁体.
- 替代磁铁为在补偿磁系统中利用异常的Nernst效应提供了一条新的途径.
- 这些发现凸显了变磁材料在热电和自旋热力电子应用中的潜力.
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