High-field multifrequency ESR in the S=52 kagome-lattice antiferromagnet KFe 3(OH) 6(SO 4) 2

Abstract

We have performed high-field multifrequency electron spin resonance (ESR) and high-field magnetization measurements in magnetic fields H of up to 53 T on single crystals of the kagome-lattice antiferromagnet KFe 3 (OH) 6 (SO 4 ) 2 . We have analyzed the magnetization curve and the ESR excitation modes for Hc by using two kinds of anisotropy origins, the Dzyaloshinsky-Moriya (DM) interactions and the single-ion anisotropy, the former of which is inevitable in a kagome-lattice antiferromagnet. We obtained good agreement between experiment and calculation for the case of the DM interactions. In addition, we have clarified the origin of a field-induced metamagnetic transition observed in the magnetization curve and determined the intraplane and interplane exchanges and the DM interaction parameters. © 2012 American Physical Society.