Investigation of glassy behavior in lead barium ytterbium tantalate relaxors

The glassy behavior of lead barium ytterbium tantalate relaxors has been investigated. The frequency dependence of the temperature, T′m (the temperature corresponding to the maximum value dielectric constant) is analyzed using Vogel–Fulcher relation and power law. The fitting parameters reveal that the power law explains the relaxation mechanism much better than the Vogel–Fulcher relation. The temperature dependence of dielectric constant at temperatures much higher and lower than T′m is analyzed by two exponential functions, which gives an idea about the production of polar clusters at high temperature and the distribution of freezing temperatures at lower temperature.