Microstructure Evolution and Thermoelectric Property of Pt-PtRh Thin Film Thermocouples

摘要

Due to their small size, extremely fast response, and low cost, refractory metallic thin film thermocouples (TFTCs) are well suited for the surface temperature measurement of hot components. In this study, PtRh films with different amounts of Rhodium (10% and 13%) were deposited with direct current magnetron sputtering and annealed at different temperatures in air. The chemistry, microstructure, and resistivity of the films were investigated. Type S (Pt10%Rh-Pt) and type R (Pt13%Rh-Pt) TFTC were fabricated on alumina substrates. Rhodium segregation at the surface of PtRh film was observed, and the variation of the thermoelectric properties of TFTCs was discussed based on the chemistry and microstructure of PtRh films.