在Fe替代的化物CoS2中的少数旋转导电状态2
Anustup Mukherjee1, Alaska Subedi1
1CPHT, CNRS, École Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau, France.
Journal of physics. Condensed matter : an Institute of Physics journal
|September 27, 2023
概括
该研究发现,和铁二硫化物合金 (Co1-xFexS2) 不是半金属的,因为在费米水平上,少数旋转状态总是存在. 这表明在合金系列中存在电荷载体.
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:
- 甲二硫化 (CoS2) 和其与铁二硫化 (FeS2) 的合金的半金属性质一直是长期争论的主题.
- 半金属材料由于其独特的电子特性,对旋转应用至关重要,因为它们在一个旋转方向上表现出金属行为,而在另一个方向上表现出半导体行为.
研究的目的:
- 通过第一原则计算,研究Co1-xFexS2合金系列的电子结构.
- 通过分析电子状态在费米水平的占用来确定这些材料是否表现出半金属性质.
主要方法:
- 基于密度函数理论 (DFT) 的第一原则计算.
- 利用局部密度近似 (LDA) 和通用梯度近似 (GGA) 交换相关函数来评估它们对电子结构的影响.
- 分析了带结构和状态的密度,重点关注少数旋转状态及其在费米水平上的占用,作为Fe度的函数.
主要成果:
- 第一原则计算显示,在整个Co1-xFexS2系列中,少数旋转状态在费米水平上占有有限的位置.
- 铁 (Fe) 度的增加扩大了少数旋转通道中最低的导电带,相对于费米水平而言降低了这些状态,这与刚性带的预期相反.
- 随着Fe含量的增加,交易所分裂会减少,进一步使少数旋转状态更接近费米水平.
结论:
- Co1-xFexS2合金系列不是半金属的,因为少数旋转电荷载体在费米水平上始终存在.
- 这些发现得到了少数旋转带穿越费米水平的实验观测的支持,这些观测在史泰基度 CoS2.
- 这些结果澄清了Co1-xFexS2的电子行为,影响了它们在需要特定自旋依赖电子性质的领域的潜在应用.
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