Extremely low temperature coefficient of resistivity in antiperovskite compounds M_σGa_(1-σ)CFe_3 (M = Cu, Ag)

摘要

We report the effects of substitution of Cu/Ag/Zn/Sn for Ga on the temperature coefficient of resistivity (TCR) of antiperovskite GaCFe_3. With both Cu and Ag dopants increasing, the resistivity displays a peak over a broad temperature range (or low TCR value) around room temperature. As a result, the Cu/Ag dopant can sufficiently optimize the TCR value. For Ag_(0.05)Ga_(0.95)CFe_3, the averaged TCR values are less than 10.74 ppm/K (215-350 K) and, especially, as low as 2.51 ppm/K (260-300 K). Similarly, the averaged TCR values are 28.87 ppm/K (220-273 K) in Cu_(0.05)Ga_(0.95)CFe_3 and 19.20 ppm/K (235-287 K) in Cu_(0.1)Ga_(0.9)-CFe_3. Considering the extremely low averaged TCR value, broad temperature range around room temperature, friendly to the environment, and good thermostability, the series of Cu_xGa_(1-x)CFe_3 and Ag_xGa_(1-x) CFe_3 can be promising low TCR materials.