A¹³³Cs NMR Spin-Lattice Relaxation Study in Incommensurate Cs₂CdI₄

Abstract

133Cs NMR spin-lattice relaxation times(Ti) in crystalline Cs 2 CdI 4 were measured at 225 -373 K. The critical exponent ( of T\ observed near the normal-incommensurate transition in the normal phase was determined to be 0.62 ± 0.03, in good agreement with the predicted value for three-dimensional XK-model. The frequency dependent T\ in the incommensurate phase could be explained by the fluctuation of amplitudon and small gap phason.