Tunable room-temperature zero temperature coefficient of resistivity in antiperovskite compounds Ga_(1-x)CFe_3 and Ga_(1-y)Al_yCFe_3

摘要

The effects of the Ga content and the substitution of Al for Ga on the temperature coefficient of resistivity (TCR) of antiperovskite GaCFe_3 have been investigated systematically. Our results indicate the value of TCR and its temperature range can be tuned by altering chemical compositions. With decreasing the Ga content in Ga_(1-x)CFe_3 or increasing Al dopant in Ga_(1-y)Al_yCFe_3, the sign of TCR changes from positive to negative and room-temperature zero TCR material can be achieved. Typically, the optimized TCR values are about-5.72 ppm/ K(265-315K) and -14.68 ppm/K(280-320 K) for Gao_(0.95)CFe_3 and Ga_(0.85)Al_(0.15)CFe_3, respectively. The possible mechanisms for the observed low TCR are discussed.