哈伯德U校正对二维材料电子和磁性特性的影响:一项高通量研究
Sahar Pakdel1, Thomas Olsen1, Kristian S Thygesen1
1Computational Atomic-scale Materials Design (CAMD), Department of Physics, Technical University of Denmark, Kgs. Lyngby, Denmark.
概括
哈伯德U校正改善了对二维材料的带隙预测,但使格子常数恶化. 这种纠正减少了磁交换合和异构性,这表明这些过渡金属材料的基里温度较低.
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
- 计算材料科学科学 计算材料科学
背景情况:
- 准确的电子结构计算对于理解和设计新型材料至关重要.
- 含有3D过渡金属的二维 (2D) 材料表现出不同的电子和磁性特性.
- 哈伯德U校正经常在密度函数理论 (DFT) 中使用,以改进相关系统的描述.
研究的目的:
- 系统地调查哈巴德U校正对2D材料与3D过渡金属电子结构和磁性质的影响.
- 评估PBE和PBE+U近似的准确性与各种材料属性的实验数据相比.
- 为638种二维材料提供一个全面的计算属性的数据集.
主要方法:
- 密度函数理论 (DFT) 计算使用PBE和PBE+U近似值.
- 计算晶体结构,带间隙,磁矩,交换合和磁性异构.
- 理论预测与实验数据的系统比较.
主要成果:
- 发现PBE+U近似与实验相比,会使格子常数的准确性恶化.
- 哈伯德U校正显著影响带间隙,在21%的研究材料中诱导金属到绝缘体的过渡.
- 磁交换能量和异性质参数通过U校正系统地减少,而磁时刻显示弱依赖.
结论:
- PBE近似为这些二维材料提供了更准确的格子常数.
- 哈伯德U校正对于准确预测带间隙和金属到绝缘体过渡至关重要.
- 由于减少了磁交换相互作用,U校正导致预测的基里温度降低.
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