Lattice Anisotropy in Antiferromagnetic Chromium

Abstract

Thermal‐expansion and magnetostriction measurements on single‐Q, single‐crystal chromium give the lattice parameter ratios in the transverse spin‐density‐wave phase, through the spin‐flip transition, and in the longitudinal spin‐density‐wave phase. The spin‐flip transition is found to be accompanied by anisotropic discontinuities in length, resulting in a net volume dilatation of 1.4×10⁻⁶ with decreasing temperature. The Q direction is found to be the longest axis at 300°K and to bcome the shortest axis below about 220°K.