Na NMR evidence for charge order and anomalous magnetism in Na xCoO2

Abstract

The aligned single phase powder samples were provided by the material synthesis and characterization of a sodium (Na) nuclear magnetic resonance (NMR) evidence for change order and anomalous magnetism in NaxCoO 2. Calculations in a point charge model which applied on the fully ionized Na site were also performed. Three Na sites were identified from their single valued quadrupole effects and magnetic shifts. A very intriguing metallic phase with a magnetism which resembles at high T that of local moments with large antiferromagnetic interactions was revealed.