Transverse ordering of an antiferromagnet in a field with oblique angle to the easy axis

Abstract

Motivated by the recent experimental observations [Phys Rev B 57 R11051 (1998)] of transverse spin ordering in FeBr_2 induced by a magnetic field with oblique angle to the easy axis of the system, we performed extensive Monte Carlo simulations of a classical anisotropic Heisenberg model. We have calculated the specific heat and the parallel and perpendicular components of the magnetisation as well as the antiferromagnetic order parameter and studied these quantities as a function of temperature. A tilted spin-flop phase is obtained for certain parameter values. Many of the effects occuring in connection with this phase agree qualitatively well with the experimental facts.