Anisotropic exchange in GdGa

TL;DR

This paper investigates how anisotropic exchange interactions in GdGa lead to a non-collinear, canted magnetic ground state, with a model that aligns well with experimental observations of canting angles and entropy changes.

Contribution

It introduces a model considering anisotropic exchange interactions that explains the non-collinear ground state in GdGa, highlighting the competition between intra- and inter-sublattice exchanges.

Findings

Model reproduces experimental canting angles

Explains competition between collinear and non-collinear states

Matches observed entropy changes 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.