Magnetostriction-driven muon localisation in an antiferromagnetic oxide

• DOI: 10.48550/arxiv.2305.12237
• Publication Date: 2023-01-01
• Authors: Pietro Bonfà; Ifeanyi John Onuorah; Franz Lang; Iurii Timrov; Lorenzo Monacelli; Chennan Wang; Xiao Sun; O. Petracic; Giovanni Pizzi; Nicola Marzari; Stephen J. Blundell; R. De Renzi
• Keywords: Muon spin spectroscopy; Precession

Magnetostriction drives a rhombohedral distortion in the cubic rock salt antiferromagnet MnO at N\'eel temperature $T_{N}=118$ K. As an unexpected consequence we show that this acts to localize site of implanted muon due accompanying redistribution electron density. This lifts degeneracy between equivalent sites, resulting single observed precession frequency. Above $T_{N}$, instead becomes delocalized around network sites. Our first-principles simulations based on Hubbard-corrected density-functional theory and molecular dynamics are consistent with our experimental data help resolve long-standing puzzle regarding MnO, as well having wider applicability other magnetic oxides.