Invar-like behaviours in an itinerant-electron antiferromagnet

Abstract

By making use of the Landau - Ginzburg energy expansion up to the sixth power of the sublattice magnetization density, the spontaneous volume magnetostriction and the dependence on pressure of the Néel temperature in an itinerant-electron antiferromagnet are discussed. The antiferromagnetic moment is found to show first-order and second-order transitions at - according to the values of the Landau coefficients. It is shown that the difference between the spontaneous volume magnetostrictions at T = 0 and is large and the P-dependence of becomes anomalously large when a certain condition is satisfied by the Landau coefficients.