Phases of anisotropic dipolar antiferromagnets

TL;DR

This paper investigates the phase behavior of classical dipolar antiferromagnets on cubic lattices, analyzing how anisotropy and exchange interactions influence various magnetic phases through simulations and theoretical methods.

Contribution

It provides a detailed analysis of phase transitions, especially the spin reorientation phase, in anisotropic dipolar antiferromagnets using Monte Carlo simulations and mean field theory.

Findings

Identification of how anisotropy constants affect phase stability.

Detailed characterization of the spin reorientation phase and its broken symmetries.

Discovery of a reverse spin reorientation transition.

Abstract

We study systems of classical magnetic dipoles on simple cubic lattices with dipolar and antiferromagnetic exchange interactions. By analysis and Monte Carlo (MC) simulations, we find how the antiferromagnetic phases vary with uniaxial and fourfold anisotropy constants, C and D, as well as with exchange strength J. We pay special attention to the spin reorientation (SR) phase, and exhibit in detail the nature of its broken symmetries. By mean field theory and by MC, we also obtain the ratio of the higher ordering temperature to the SR transition temperature, and show that it depends mainly on D/C, and rather weakly on J. We find a reverse SR transition.