Verification of high throughput simultaneous measurement for Seebeck coefficient, resistivity, and thermal diffusivity of thermoelectric materials

Development of thermoelectric conversion materials which have better figure-of-merit, Z, has been actively performed, and high throughput Z evaluation is necessary. Though Seebeck coefficient and electrical resistivity are relatively easily measured, the thermal diffusivity is not. To overcome this, novel simultaneous measurement method for the measurement of the three thermoelectric properties with a thermocouple probe and a ceramic heater has been proposed. Seebeck coefficient and electrical resistivity are measured using the steady-state method with 4 probes, and the thermal diffusivity is measured using the periodic heating method. In this research, the concept and development of the simultaneous measurement systems in a wide temperature range to make it easy, fast, and precise by adjusting the measurement parameters such as the frequency range of periodic heating, heating power, and by adopting new analysis method. Seebeck coefficient, electrical resistivity, and thermal diffusivity of Bi2Te3, Ni, and constantan and the thermal diffusivity of Al2O3 are evaluated from room temperature to high temperature of 800 K.