Possible charge disproportionation in 3R-AgNiO2 studied by neutron powder diffraction

Jaiho Chung, J. H. Lim, Y. J. Shin, J. S. Kang, D. Jaiswal-Nagar, K. H. Kim

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Using neutron-scattering techniques, we have investigated the nuclear and the magnetic structures of the triangular antiferromagnet 3R-AgNiO2. The symmetry analysis based on the group theory suggests that the √3×√3 charge order proposed for 2H -AgNiO2 will have a monoclinic symmetry if present in the trigonal lattice of 3R-AgNiO 2. The Rietveld refinement shows that symmetry reduction in the NiO2 layer is consistent with the prediction of the group theory. The pair density function consistently shows that the nearest-neighbor Ni-O bonds split into two groups separated by approximately 0.1 Å. The antiferromagnetic Bragg peaks observed below TN=25 K can be described by the propagation vector k= (0,1,0) of the monoclinic unit cell. The similarities of the local structure and the antiferromagnetic order strongly suggest that the novel charge order observed in 2H-AgNiO2 also exists in 3R-AgNiO2.

Original languageEnglish
Article number214417
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume78
Issue number21
DOIs
Publication statusPublished - 2008 Dec 1

    Fingerprint

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

Cite this