The unusual resistivity behavior and correlated magnetic properties of antiperovskite Mn₃Ag_1-xM_xN (M = Sn, Zn) compounds

The effect of Sn-or Zn-substitution on the temperature coefficient of electrical resistivity of antiperovskite Mn3AgN compound was evaluated based on electrical resistivity, magnetization, and specific heat measurements. The non-doped Mn₃AgN compound exhibited a moderately low temperature coefficient of electrical resistivity (123 ppm/K) at temperatures above 277 K. By 40 atomic% doping with Sn, a remarkably low coefficient of 23 ppm/K was achieved. For the formulation Mn₃Ag_0.5Zn_0.5N, Zn substitution produced a low coefficient of 35 ppm/K over a much wider temperature range than achieved with Sn for temperatures above 227 K. Although the origin of the observed unusual temperature dependence of the electrical resistivity seemed complicated, the data indicated that substitution of Ag in Mn₃AgN is a promising means of developing materials with an excellent low temperature coefficient of electrical resistivity for practical applications.