Electrical behaviour of 0.80Pb[(Mg,Zn)1/3Ta2/3]O3-0.20PbTiO3 relaxor

Polycrystalline 0.80Pb[(Mg2/3Zn1/3)1/3Ta2/3]O3-0.20PbTiO3 (PMZT-PT) having a tetragonal perovskite type structure was prepared by the high temperature solid-state reaction method. Dielectric studies showed the relaxor behaviour with diffuse phase transition. High value of εm>8000 was realized with Tm (phase transition temperature) at 57 °C at 1 kHz. The frequency dependence of Tm has been modeled using Vogel-Fulcher relation. The dielectric relaxation in the present system was found analogous to the magnetic relaxation in spin-glass system. Complex impedance analysis indicated the system undergoing a polydispersive non-Debye type dielectric relaxation. The relaxation behaviour in PMZT-PT was also probed through admittance spectroscopy.