DYNAMICS OF DOMAIN-WALLS IN FERRODISTORTIVE MATERIALS .2. APPLICATIONS TO PB5GE3O11-TYPE AND SBSI-TYPE FERROELECTRICS

In this article we apply the theory developed in the previous publication to the uniaxial displacive ferroelectrics Pb5Ge3O11 and SbSI. We show that the parameters of our model can be determined from available experimental data for these substances. The values obtained are physically reasonable. With no adjustable parameters we calculate for lead germanate the wave-number and temperature dependence of the low-temperature central peak, the density of domain walls, and the polarization switching. For SbSI we evaluate the temperature and pressure dependence of the low-temperature central peak. The theoretical results agree quantitatively with the experimental data. We predict the, as yet unmeasured, temperature-dependent wall diffusion coefficient in Pb5Ge3O11 and the mobility of its domain walls in a field. © 1979 The American Physical Society.