Application of Antiperovskite Manganese Nitride to Standard Resistor

Abstract

CuMn-related alloys as typified by Manganin, and NiCr-related alloys such as Evanohm are widely used for the materials of standard and precision resistors. These materials have a broad resistance peak around room temperature in the resistance-temperature curve and resistance is stable and insensitive to temperature change and fluctuation around the peak. Therefore these alloys are recognized as superior materials for standard and precision resistors. The antiperovskite manganese nitride compounds, Mn₃Ag_1-xCu_xN, also show a broad resistance-temperature curve around room temperature and the temperature coefficient is comparable to those of Manganin alloys. We found out that this curvature and the peak temperature can be controlled by co-doping with Cu and In or Fe and we demonstrated that the Mn_3.03Ag_0.62Cu_0.19In_0.15N shows a low temperature second-order coefficient of resistor, 0.2 (μΩ/Ω)/K². We have also revealed that the drift rate of the resistance can be decreased by shaping a sintered sample to the 4-terminal fashion.