Abstract :
Relaxor ferroelectric behaviour has been observed for lead magnesium niobate–lead zirconate (0.7PMN–0.3PZ) ceramic. The freezing temperature obtained from fitting of dielectric data to the Vogel–Fulcher equation is very close to the dielectric-maximum temperature and to the temperature of collapse of remanant polarization. The temperature dependence of the spontaneous polarization follows a modified Neelʹs equation. Specific-heat measurement shows canonical glass-like behaviour, and the value of the glass-transition temperature is very close to the freezing temperature obtained from the Vogel–Fulcher equation. All the observations together indicate that 0.7PMN–0.3PZ ceramic behaves like a dipolar glass.
