Cluster distribution in paraelectricKH2AsO4. II.As75spin-spin and spin-lattice relaxation

The ${}_{}{}^{75}{}_{}{}^{}\mathrm{As}$ spin-lattice relaxation rate as well as the ${}_{}{}^{75}{}_{}{}^{}\mathrm{As}$ homogeneous and inhomogeneous linewidth has been measured in paraelectric ${\mathrm{KH}}_2$ ${\mathrm{AsO}}_4$ as a function of temperature and orientation of the crystal in the external magnetic field. The results show that we are dealing (on the NMR time scale) with a continuous distribution of quasistatically polarized crystal regions ranging from zero local polarization to fully polarized states, which is symmetric as far as the sign of the polarization is concerned and strongly peaked at zero polarization. The distribution becomes broader and broader as the Curie temperature is approached from above.