Anisotropic exchange in GdGa

Abstract

In this work we discuss the non-collinear ground-state reported for GdGa on the basis of a model Hamiltonian considering anisotropic exchange interactions. We show that a competition between intra and inter-sublattice exchange interactions can lead to a canted structure, which competes with a collinear (ferro or antiferromagnetic) order. The mean-field thermodynamic analysis of the model for $S=7/2$ shows a good agreement between calculated and reported experimental data of the canting angle and isothermal entropy change for GdGa.