Walmsley P, Fisher I R
Geballe Laboratory for Advanced Materials and Department of Applied Physics, Stanford University, Stanford, California 94305-4045, USA.
Rev Sci Instrum. 2017 Apr;88(4):043901. doi: 10.1063/1.4978908.
Measurements of the resistivity anisotropy can provide crucial information about the electronic structure and scattering processes in anisotropic and low-dimensional materials, but quantitative measurements by conventional means often suffer very significant systematic errors. Here we describe a novel approach to measuring the resistivity anisotropy of orthorhombic materials, using a single crystal and a single measurement that is derived from a π4 rotation of the measurement frame relative to the crystallographic axes. In this new basis, the transverse resistivity gives a direct measurement of the resistivity anisotropy, which combined with the longitudinal resistivity also gives the in-plane elements of the conventional resistivity tensor via a 5-point contact geometry. This is demonstrated through application to the charge-density wave compound ErTe, and it is concluded that this method presents a significant improvement on existing techniques, particularly when measuring small anisotropies.
电阻率各向异性的测量可以提供有关各向异性和低维材料中电子结构及散射过程的关键信息，但采用传统方法进行定量测量时常常会出现非常显著的系统误差。在此，我们描述了一种测量正交晶系材料电阻率各向异性的新方法，该方法使用单晶，并通过测量框架相对于晶轴进行π/4旋转后的单次测量来实现。在这个新的坐标系中，横向电阻率直接测量了电阻率各向异性，再结合纵向电阻率，通过五点接触几何结构还能得到传统电阻率张量的面内分量。通过将其应用于电荷密度波化合物ErTe进行了验证，得出的结论是，该方法相较于现有技术有显著改进，尤其是在测量小的各向异性时。
