Antiferromagnetism in metals

Abstract

Neutron diffraction studies of chromium and manganese by Shull & Wilkinson have disclosed the existence of a partial antiferromagnetic ordering in these metals, dissimilar in several respects from the antiferromagnetism which occurs in compounds such as MnF 2 and MnO. The present paper proposes a simple formulation of an energy-band theory of antiferromagnetism based on the assumption that the magnetically effective electrons are in nonlocalized states. It is shown how- this approach leads to an understanding of the differences between antiferromagnetic metals and antiferromagnetic compounds, which are better treated by assuming that the electrons are in localized states. In particular, it is shown why Cr and Mn do not present observable anomalies in specific heat and susceptibility at the Curie point. Finally, it is pointed out that the occurrence of antiferromagnetism in palladium may be the explanation of the gentle susceptibility maximum at 80° K observed by Hoare & Mathews.