Study of relaxor behavior of 0.7Pb(Mg<SUB>1/3</SUB>Nb<SUB>2/3</SUB>)O<SUB>3</SUB>-0.3PbTiO<SUB>3</SUB> thin films

Relaxor properties of polycrystalline 0.7Pb(Mg1/3Nb2/3 )O3 -0.3PbTiO3 (PMN-PT) thin films were studied in terms of the diffuse nature of phase transition along with the frequency dispersion of temperature (Tm ) at which the dielectric constant exhibits maximum value. Existence of remnant polarization (Pr ) above the phase transition temperature, which is a characteristic property of typical relaxor ferroelectric has also been observed in the present case. The films exhibited a gradual decrease of remnant polarization with increase of temperature. Among the different models of relaxor ferroelectric, Vogel-Fulcher model has been found to be suitable to describe the frequency dispersion of Tm in this case. Freezing of dipole moment with decrease of temperature was thought to be the origin of the temperature dependence of dielectric dispersion