Abstract
The magnetic ground states of the isostructural double perovskites BaNaOsO and BaLiOsO are investigated with muon-spin relaxation. In BaNaOsO long-range magnetic order is detected via the onset of a spontaneous muon-spin precession signal below , while in BaLiOsO a static but spatially disordered internal field is found below 8 K. A probabilistic argument is used to show from the observed precession frequencies that the magnetic ground state in BaNaOsO is most likely to be low-moment () ferromagnetism and not canted antiferromagnetism. BaLiOsO is antiferromagnetic and we find a spin-flop transition at . A reduced osmium moment is common to both compounds, probably arising from a combination of spin-orbit coupling and frustration.
- Received 8 February 2011
DOI:https://doi.org/10.1103/PhysRevB.84.144416
©2011 American Physical Society