Automated Instrumentation for High-Temperature Seebeck Coefficient Measurements

In this work, we report the fabrication of fully automated experimental setup for high temperature Seebeck coefficient ({\alpha}) measurement. The K-type thermocouples are used to measure the average temperature of the sample and Seebeck voltage across it. The temperature dependence of the Seebeck coefficients of the thermocouple and its negative leg is taken care by using the integration method. Steady state based differential technique is used for {\alpha} measurement. Use of limited component and thin heater simplify the sample holder design and minimize the heat loss. The power supplied to the heater decides the temperature difference across the sample and the measurement is carried out by achieving the steady state. The LabVIEW based program is built to automize the whole measurement process. The complete setup is fabricated by using commonly available materials in the market. This instrument is standardized for materials with a wide range of {\alpha} and for the wide range of {\Delta}T across the specimen. For this purpose, high temperature measurement of {\alpha} of iron, constantan, bismuth, and Bi_0.36 Sb_1.45 Te_3 samples are carried out and data obtained from these samples are found to be in good agreement with the reported data.

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