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Incommensurate magnetic order in Ag$_{2}$NiO$_{2}$

J. Sugiyama·Y. Ikedo·K. Mukai·J. H. Brewer·E. J. Ansaldo·G. D. Morris·K. H. Chow·H. Yoshida·Z. Hiroi
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Abstract

The nature of the magnetic transition of the half-filled triangular antiferromagnet Ag$_{2}$NiO$_2$ with $T_{\rm N}$=56K was studied with positive muon-spin-rotation and relaxation ($μ^+$SR) spectroscopy. Zero field $μ^+$SR measurements indicate the existence of a static internal magnetic field at temperatures below $T_{\rm N}$. Two components with slightly different precession frequencies and wide internal-field distributions suggest the formation of an incommensurate antiferromagnetic order below 56 K. This implies that the antifrerromagnetic interaction is predominant in the NiO$_2$ plane in contrast to the case of the related compound NaNiO$_2$. An additional transition was found at $\sim$22 K by both $μ^+$SR and susceptibility measurements. It was also clarified that the transition at $\sim$260 K observed in the susceptibility of Ag$_{2}$NiO$_{2}$ is induced by a purely structural transition.

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J. Sugiyama, Y. Ikedo, K. Mukai, J. H. Brewer, E. J. Ansaldo, G. D. Morris, K. H. Chow, H. Yoshida, Z. Hiroi. 2006-06-09. Incommensurate magnetic order in Ag$_{2}$NiO$_{2}$. https://arxiv.org/abs/cond-mat/0606229

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