Antiperovskite Manganese Nitride Standard Resistor

The antiperovskite manganese nitride compound Mn₃Ag_1-xCu_xN has a broad resistivity-temperature curve around room temperature that is comparable with the Manganin alloy. This curvature and the peak temperature can be adjusted by codoping with Cu and In or Fe. The drift rate of the resistance value was strongly affected by the condition of the four-terminal contact and the shape of the sample. Samples with spot-welded contacts show lower resistance drift rates than samples with Ag-paste contacts. The four-terminal-shaped sample has a drift rate that is 80 times lower than the normal cuboid-shaped sample. We confirmed that the Mn₃AgN sample has a sufficiently low-thermal electromotive force against copper that is less than a few microvolts per kelvin. We expect that this antiperovskite compound could be used as a material for precision resistors and could improve the temperature coefficient of resistors for developing metrology standards.