High-field multifrequency ESR in the S=5/2 kagome-lattice antiferromagnet KFe[subscript 3}(OH)[subscript 6](SO[subscript 4])[subscript 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[subscript 3](OH)[subscript 6](SO[subscript 4])[subscript 2]. We have analyzed the magnetization curve and the ESR excitation modes for H∥c 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.