Investigation of glassy behavior of lead magnesium niobate relaxors

The dielectric behavior of a solid solution, 10 mol % lead titanate in lead magnesium niobate, vs temperature at different frequencies is measured and analyzed. The shortcomings of the Vogel-Fulcher relationship are discussed. A more reasonable new relationship: omega = omega(0) exp[-(T-0/T-m)(p)] is introduced to characterize the relation between the frequency (omega) and the temperature (T-m) at the dielectric constant maximum of the relaxer ferroelectrics. The value of the parameter p in the relationship can be used to characterize the dielectric relaxation strength of relaxer ferroelectrics as well as the relation among the ferroelectrics, the relaxer ferroelectrics, the Debye medium and glass. (C) 1996 American Institute of Physics.