Manganese nitride compound standard resistor

The manganese nitride antiperovskite compound, Mn
₃
Ag
_1-x
Cu
_x
N shows broad resistivity-temperature curve around room temperature. This curvature and the peak temperature can be adjusted by In or Fe doping. The drift-rate of the resistance value was strongly affected by the condition of the 4-terminal contact and the shape of the sample. The sample with 4-terminal shape shows 90 times lower drift rate of resistance than the normal cuboid shape sample. We confirmed that the Mn
₃
AgN sample shows low enough thermal electromotive force against copper less than a few μV/K. We expect that this antiperovskite compound can be used as a material of precision resistors and has a possibility to improve the temperature coefficient of resistors including the purpose for standards.