Methods for the measurement of the Seebeck coefficient to high temperatures
Ryozo Kato, Yukio Maeda, Akikazu Maesono, Ronald P Tye
Two methods have been developed for the measurement of the Seebeck coefficient to high temperatures. One is a low frequency (< 6 Hz) AC method used primarily for semiconductors up to 1200 K. A combination of laser heating and a sensitive lock-in amplifier ensures a higher measurement precision than that attained by previous AC methods with higher frequencies. The other measures the Seebeck coefficient, electric resistance, heat flux, and temperature profiles of gradient composite thermoelectric elements up to 1500 K under conditions of large temperature gradients up to 800 K. Verification of the performance of each is described together with comparisons of results on different materials.