Electrical Resistivity and Hall Effect of Cr-ModifiedMn2Sb

Electrical resistivity has been measured as a function of temperature for single crystals of ${\mathrm{Mn}}_{2-x}{\mathrm{Cr}}_x\mathrm{Sb}$, where $0.01<x<\mathrm{}0.2\mathrm{}$. These materials exhibit exchange inversion transitions, and their resistivity at a given temperature depends almost entirely on the magnetic ordering and is essentially independent of the chromium concentration for temperatures greater than 100°K. These transitions are first order, and the thermal hysteresis associated with them decreases as the transition temperature increases. External magnetic fields lower the transition temperatures, and the extent of this decrease, ${\left(\frac{\partial H}{\partial T_s}\right)}_P$, is a function of the zero-field transition temperature. Hall effect measurements at room temperature indicate that the effective number of current carriers is 1.0 hole per molecule for compounds with either ferrimagnetic or antiferromagnetic ordering.