Theory of the Field Dependence of the Néel Temperature in Quasi One-Dimensional Antiferromagnets

Abstract

The field dependence of the Néel temperature T_N of an antiferromagnet is explained by use of the Oguchi first mean field theory. It is shown that T_N increases in a uniform magnetic field of appropriate magnitude when the spin entropy at T_N is large. The latter condition occurs when the antiferromagnet is quasi one-dimensional with small anisotropy energy.