Nearly zero temperature coefficient of resistivity in antiperovskite compound CuNMn3

The temperature dependent structural, magnetic, and transport properties of a Mn-based compound CuNMn3 with an antiperovskite structure were investigated. A ferrimagnetic transition occurs near 150 K, which coincides with the structural transition temperature from cubic to tetragonal symmetry. Below 150 K, the resistivity of this compound shows a metallic behavior. Above 150 K, however, the variation of resistivity with temperature is almost negligible, exhibiting nearly zero temperature coefficient of resistivity (TCR). Its TCR value is about 46 ppm/K near room temperature, which is about two orders of magnitude smaller than those of pure metals like Cu and Al.