Anomalous temperature evolution of the internal magnetic field distribution in the charge-ordered triangular antiferromagnet AgNiO2.

Research paper by T T Lancaster, S J SJ Blundell, P J PJ Baker, M L ML Brooks, W W Hayes, F L FL Pratt, R R Coldea, T T Sörgel, M M Jansen

Indexed on: 01 Feb '08Published on: 01 Feb '08Published in: Physical review letters


Zero-field muon-spin relaxation measurements of the frustrated triangular quantum magnet AgNiO2 are consistent with a model of charge disproportionation that has been advanced to explain the structural and magnetic properties of this compound. Below an ordering temperature of TN=19.9(2) K we observe six distinct muon precession frequencies, due to the magnetic order, which can be accounted for with a model describing the probable muon sites. The precession frequencies show an unusual temperature evolution which is suggestive of the separate evolution of two opposing magnetic sublattices.