Sharma Shailja, Yadav C S
School of Basic Sciences, Indian Institute of Technology Mandi, Mandi 175075, HP, India.
Rev Sci Instrum. 2020 Dec 1;91(12):123907. doi: 10.1063/5.0031544.
A new experimental setup is designed for the measurement of Seebeck and Nernst coefficients on the single crystal flakes and polycrystalline samples. The setup utilizes the multifunctional probe assembly of the physical property measurement system by Quantum Design, Inc. and can measure in the temperature range of 1.8 K-380 K up to 8 T magnetic fields. The experimental measurement was fully automated through a computer using the code written in LabVIEW software. The setup is capable of measurements on samples as small as 2 × 1 mm in size and thickness as small as a few micrometers, which is quite important for the crystal flakes grown using the vapor transport method. The determination of the coefficients is based on the quasi-static approach, with the thermal gradient of 0.2 K-1.2 K across the sample in the measured temperature range of 1.8 K-300 K. The sensitivity of the instrument is better than 0.1 µV/K, and the accuracy is better than ∼0.5 µV/K, which can be further improved with the better quality of electrical contacts on the sample. The Seebeck and Nernst coefficient measurements performed on some well-studied semimetallic (bismuth), thermoelectric (BiSe), and superconducting (FeTeSe) systems are also presented.
设计了一种新的实验装置，用于测量单晶薄片和多晶样品的塞贝克系数和能斯特系数。该装置利用了美国量子设计公司物理性能测量系统的多功能探头组件，可在1.8 K至380 K的温度范围内、高达8 T的磁场中进行测量。实验测量通过计算机使用LabVIEW软件编写的代码实现了完全自动化。该装置能够对尺寸小至2×1 mm、厚度小至几微米的样品进行测量，这对于采用气相传输法生长的晶体薄片非常重要。系数的测定基于准静态方法，在1.8 K至300 K的测量温度范围内，样品上的热梯度为0.2 K至1.2 K。仪器的灵敏度优于0.1 μV/K，精度优于约0.5 μV/K，通过改善样品上的电接触质量可进一步提高。还展示了对一些经过充分研究的半金属（铋）、热电（BiSe）和超导（FeTeSe）系统进行的塞贝克系数和能斯特系数测量。
