Experimental Demonstration of the Existence and Subsequent Breakdown of Triad Dynamics in the Spin-Glass CuMn

Abstract

ESR measurements of a CuMn spin-glass performed as a function of frequency and magnetic field angle confirm that there is a mode splitting as predicted by the triad model. At large field angles neither the triad nor vector models are consistent with the data for any assignment of anisotropy constants, suggestive of a breakdown in the assumption of a rigid spin rotation. However, at 180° the data are well described by a vector model. Determinations of the anisotropy constants by various experimental methods are discussed.