Advancing Thermopower Measurement: Probe Design and Seebeck Coefficient Analysis

The thermoelectric effect enables the direct conversion of heat into electrical energy, with broad applications in power generation and temperature control. This research focuses on measuring the material’s Seebeck coefficient, defined as the ratio of generated voltage to temperature difference. In our strongly correlated electron laboratory at Fresno State, we developed a measurement probe to evaluate the thermopower of different intermetallic compounds. Initial experiments on nickel alloy 201 (Ni) and 99.95% platinum (Pt) over a temperature range of 11 K to 300 K showed that the measured thermopower values aligned within 3% of the literature data above 100 K. However, significant deviations were observed at lower temperatures due to the type-T differential thermocouple and background wiring effects, highlighting the need for probe refinements to minimize these issues. Our current work involves enhancing the probe by building hot and cold platforms on sapphire plates for electrical isolation and optimized thermal conductance. The design includes dual sample holders and two Cernox thermometers, with the hot platform adjustable to accommodate various sample sizes. We are currently working on optimizing the wiring. Additionally, we developed LabVIEW programs for calibration and analysis. Our future goal is to complete all necessary hardware for the probe design and measure the Seebeck coefficient of Ni and Pt to verify the accuracy of the new probe design.