High temperature transport probr for thermopower and resistivity measurements

摘要

We have recently developed a device to measure resistivity and Seebeck values of a material as a function of temperature over a range of 80K These measurements overlap in temperature with our existing apparatus (4K < T < 320K). These measurements are necessary for the investigation of potential thermoelectric materials at elevated temperatures, where power generation applications are important. The probe design allows for various types of samples to be evaluated from needle like samples (L approx approx 2mm, D approx approx 50 mu m) to larger pressed peelet samples (approx approx 2mm X 10mm). Separate high temperature cartridge heaters are used to stabilize both the absolute temperature, T, as well as the temperature difference, DELTA T. Thermocouples measuring T+ DELTA T/2 and T-DELTA T/2 are also employed to measure sample voltages for resistance and thermoelectric power. Design details and measruement specifics will be discussed. Data taken on standards a ell as some research samples will be proesented.