Investigation of the magnetic ground state of GaV4S8 using powder neutron diffraction

S J R Holt,M R Lees,G Balakrishnan,C Ritter

doi:10.1088/1361-648x/abf9bb

Abstract

The magnetic ground state of polycrystalline Néel skyrmion hosting material GaV4S8 has been investigated using ac susceptibility and powder neutron diffraction. In the absence of an applied magnetic field GaV4S8 undergoes a transition from a paramagnetic to a cycloidal state below 13 K and then to a ferromagnetic-like state below 6 K. With evidence from ac susceptibility and powder neutron diffraction, we have identified the commensurate magnetic structure at 1.5 K, with ordered magnetic moments of 0.23(2) μ B on the V1 sites and 0.22(1) μ B on the V2 sites. These moments have ferromagnetic-like alignment but with a 39(8)° canting of the magnetic moments on the V2 sites away from the V4 cluster. In the incommensurate magnetic phase that exists between 6 and 13 K, we provide a thorough and careful analysis of the cycloidal magnetic structure exhibited by this material using powder neutron diffraction.

Highlights

There has been widespread interest in skyrmion hosting materials, both for their fascinating magnetic properties, as well as their potential application in fields such as spintronics [1]
In the incommensurate magnetic phase that exists between 6 and 13 K, we provide a thorough and careful analysis of the cycloidal magnetic structure exhibited by this material using powder neutron diffraction
An additional low temperature ferromagnetic-like (F-L) phase can be identified from the ac susceptibility map in figure 2, which is not present in most previously published phase diagrams

Summary

Introduction

There has been widespread interest in skyrmion hosting materials, both for their fascinating magnetic properties, as well as their potential application in fields such as spintronics [1]. GaV4S8 is a member of the lacunar spinel family (AB4X8) which has been shown to stabilise a variety of magnetic phases including a cycloidal state and Neel skyrmions [3]. It adopts a high-temperature face centred cubic F43m structure with a. We have carried out ac susceptibility measurements on a single crystal of GaV4S8 and have identified a new commensurate ferromagnetic-like zero-field phase at low temperatures that undergoes a transition to a ferromagnetic state with applied magnetic fields. We describe the magnetic structure in this low temperature commensurate phase and the incommensurate state, with reference to the existing literature

Experimental details

Ac susceptibility

Powder neutron diffraction at 9 K: incommensurate structure

Summary and conclusions

Data availability statement