Effect of High Pressure on Antiferromagnetism in Cr Alloys

Abstract

The pressure dependence of antiferromagnetic ordering in Cr☒Ru, Cr☒Mn, and Cr☒Re alloys has been investigated. At low concentrations, T_N drops very rapidly and nonlinearly with pressure up to some point and then exhibits a much slower variation with a distinct break in slope. We attribute this break in slope to a transition from communsurate phase (C) at lower pressures to an incommensurate phase (I) at higher pressures. If we extrapolate the paramagnetic (P) to incommensurate boundary back to 1 atm we obtain values for the Néel temperature (T_NI) for P ‐ I transition, if the P ‐ C transition had not occurred first. T_NI when plotted against e∕a shows a sharp break at pure Cr, in accord with theoretical predictions based on the ``depairing'' effects of impurity scattering.