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: ω=ω0 exp[−(T0/Tm)p] is introduced to characterize the relation between the frequency (ω) and the temperature (Tm) at the dielectric constant maximum of the relaxor ferroelectrics. The value of the parameter p in the relationship can be used to characterize the dielectric relaxation strength of relaxor ferroelectrics as well as the relation among the ferroelectrics, the relaxor ferroelectrics, the Debye medium and glass.