35Cl spin-lattice relaxation in incommensurate bis(4-chlorophenyl)sulfone

Journal ArticleThe 35C1 nuclear-quadrupole-resonance (NQR) spin-lattice relaxation rate in incommensurate bis(4- chlorophenyl)sulfone (BCPS) is determined by Raman processes below 60 K and by direct one-phonon processes above 60 K. The variation of the 35C1 spin-lattice relaxation rate over the incommensurate NQR frequency distribution in BCPS has been also measured at various temperatures. The results are explained in terms of phason and amplitudon contributions to the effective spin-lattice relaxation rate. In contrast to Rb2ZnCl4-type crystals the changes in the CI electric-field-gradient tensor produced by modulation wave fluctuations contain both first- and second-derivative terms