RANDOM-FIELD, DYNAMIC PROPERTIES AND PHASE-DIAGRAM PECULIARITIES OF RELAXOR FERROELECTRICS

The consideration of dynamic properties as well as static ones had sho wn that random field distroyed orderness of reference phase of relaxor s and lead to dipole glass state, mixed phase or ferroelectric phase i n dependence of random field strength. Calculations of temperature and frequency dependence of dielectric susceptibility lead to existance o f low-and high-temperature group of maxima obeyed to Vogel-Fulcher (V- F) and Arrhenius laws respectively. The V-F law and non-Debye relaxati on behavior were shown to be the consequence of random field distribut ion, which transforms one dipole Arrhenius and Debye laws into V-F and non-Debye laws respectively. Comparison of observed and calculated ch aracteristics of the relaxors is carried out.