Magnetoelasticity of Cr–Ga alloy single crystals at high pressures

Abstract

Unusual magnetic effects in an itinerant electron antiferromagnetic Cr-Pt alloy single crystal J. Appl. Phys. 93, 7269 (2003); 10.1063/1.1558610 Anomalous itinerant magnetic properties of a Cr+2.2at. % Al alloy single crystalMeasurements are reported of the pressure dependences of the elastic constants of Crϩ0.16 at. % Ga and Crϩ0.88 at. % Ga alloy single crystals through the Néel temperature of both crystals and through the incommensurate-commensurate transition temperature of the latter crystal. The long-wavelength acoustic-mode Grüneisen parameters, ␥ p , which quantify the lattice vibrational anharmonicity, are calculated from the measurements. Both alloys show, depending on the temperature, unusually large positive and negative values of ␥ p which are ascribed to strong coupling of the spin-density wave to the acoustic phonons. The nature of these interactions differs for the two alloys.