Magnetic properties and muon localization in Cr2S3

We investigate the magnetic ground state of rhombohedral chromium sulphide Cr2S3 by density functional theory. We identify the muon implantation sites, their hyperfine couplings and the role of charge states in this compound. Our calculations show that we can obtain a compensated ferrimagnetic ground state. We find that strong electronic correlations are required to correctly obtain the semiconducting band behaviour of Cr2S3 in agreement with experiment. Relying on earlier mu SR measurements, our calculations suggest that the two muon local fields in Cr2S3 are due to distinct charge states for two very close but distinct muon sites bonded between two sulphur atoms. Further analysis of the static field at the muon allows to determine by mu SR the average Cr magnetic moment in good agreement with experiment.