Antiperovskite compound standard resistor

We have evaluated the temperature coefficient of resistance around room temperature in detail of manganese nitride antiperovskite compounds, Mn₃Ag_1-xCu_xN. It has been found that the second order term of the temperature coefficient, β, depends on the Cu content. When the Cu content value, x=0.4, the compound, Mn₃Ag_0.6Cu_0.4N, has shown the lowest temperature coefficient, α₂₃ = 0.42 (μΩ/Ω)/K and β = -0.2 (μΩ/Ω)/K². 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.