在二维范德瓦尔斯晶体中发现内在铁磁
Cheng Gong1, Lin Li2, Zhenglu Li3,4
1Nano-scale Science and Engineering Center (NSEC), 3112 Etcheverry Hall, University of California, Berkeley, California 94720, USA.
Nature
|April 27, 2017
概括
在原始的二维Cr2Ge2Te6范德瓦尔斯晶体中实现了远程铁磁秩序. 这一发现使二维材料具有可调节的磁性.
科学领域:
- 材料科学
- 凝聚物质物理学
- 纳米技术
背景情况:
- 二维 (2D) 范德瓦尔斯晶体为高级应用提供独特的电子和光学性能.
- 根据默明-瓦格纳定理,在二维系统中实现远程铁磁秩序是具有挑战性的.
- 之前的诱导二维材料磁性的方法通常是局部或外部的.
研究的目的:
- 在原始的Cr2Ge2Te6原子层中报告内在的远程铁磁秩序.
- 通过使用外部磁场来研究二维铁磁体的磁转换温度的控制.
- 探索Cr2Ge2Te6对于基本的旋转研究和旋转应用的潜力.
主要方法:
- 扫描磁光克尔显微镜被用来揭示内在的铁磁秩序.
- 对过渡温度对小磁场 (< 0.3 特斯拉) 的依赖性的实验研究.
- 使用重新规范化的自旋波理论来解释观察到的磁性行为.
主要成果:
- 在原始的Cr2Ge2Te6 2D原子层中证实了内在的远程铁磁秩序.
- 这种磁性柔软的2D铁磁体的过渡温度对小的磁场非常敏感,与3D对应物不同.
- 微小的磁场诱导了显著的有效异形,超过了接近零的磁晶异形,导致了很大的自旋波激发差距.
结论:
- Cr2Ge2Te6表现出异常的取决于场的过渡温度行为,这是软的2D铁磁范德瓦尔斯晶体的特征.
- 这种材料作为一个近乎理想的二维海森堡铁磁体用于基本的旋转物理研究.
- 这些发现为超紧的自旋电子和磁电设备的新应用铺平了道路.
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