论文标题
在磁性增强的热电上，短距离抗铁磁相关性的真实空间可视化
Real-space visualization of short-range antiferromagnetic correlations in a magnetically enhanced thermoelectric
论文作者
论文摘要
短距离磁相关性可以显着增加磁性半导体的热电器，这代表了数十年来为开发高性能热电材料而引人注目的发展。在这里，我们揭示了抗磁性半导体MNTE中热电器增强磁相关的性质。 Using magnetic pair distribution function analysis of neutron scattering data, we obtain a detailed, real-space view of robust, nanometer-scale, antiferromagnetic correlations that persist into the paramagnetic phase above the Néel temperature $T_{\mathrm{N}}$ = 307 K. The magnetic correlation length in the paramagnetic state is significantly longer along the crystallographic $c$ axis than within the $ab$平面，指向各向异性磁相互作用。在无序的局部力矩接近中使用密度函数理论对自旋旋转相关性的从头算计算以定量准确性再现了该结果。这些发现构成了磁性增强的热电学相关性的第一张真实空间图片，并为未来的努力提供了通过磁方法优化热电性能的努力。
Short-range magnetic correlations can significantly increase the thermopower of magnetic semiconductors, representing a noteworthy development in the decades-long effort to develop high-performance thermoelectric materials. Here, we reveal the nature of the thermopower-enhancing magnetic correlations in the antiferromagnetic semiconductor MnTe. Using magnetic pair distribution function analysis of neutron scattering data, we obtain a detailed, real-space view of robust, nanometer-scale, antiferromagnetic correlations that persist into the paramagnetic phase above the Néel temperature $T_{\mathrm{N}}$ = 307 K. The magnetic correlation length in the paramagnetic state is significantly longer along the crystallographic $c$ axis than within the $ab$ plane, pointing to anisotropic magnetic interactions. Ab initio calculations of the spin-spin correlations using density functional theory in the disordered local moment approach reproduce this result with quantitative accuracy. These findings constitute the first real-space picture of short-range spin correlations in a magnetically enhanced thermoelectric and inform future efforts to optimize thermoelectric performance by magnetic means.
