Order Parameter Dynamics and Hydrogen Bond Potential in DKDP

Abstract

The polarization relaxation in DKDP is considered within pseudospin model in the mean field approximation. The relaxation rate is determined by the activation energy of deutrons jumps along hydrogen bonds, the equilibrium polarization, and the dielectric susceptibility. The polarization and the dielectric susceptibility were calculated in the four-particle cluster approximation. The activation energy was extracted from Raman scattering experiment by fitting of the central peak width data. The same parameters of the cluster approximation describe well the relaxation rate extracted from sound-propagation experiment.