Anomalous Thermal Expansion of Chromium near T_N

Abstract

Strong lattice relaxation associated to the diffusion rate of interstitial nitrogen reported in an earlier paper was taken into account in a determination of the excess expansivity of single crystal chromium near the antiferromagnetic to paramagnetic transition. An anomalous positive expansivity peak just below T N is thought of being the result of released magnetomechanical strain. The observations support the pinning model of antiferromagnetic domains.