Dielectric relaxation, phase transition and Rietveld studies of perovskite [Pb_0.94Sr_0.06][(Mn_1/3Sb_2/3)_0.05(Zr_0.52Ti_0.48)0.95]O3 ceramics

Abstract

The frequency-dependent dielectric relaxation of [Pb_0.94Sr_0.06][(Mn_1/3Sb_2/3)_0.05(Zr_0.52Ti_0.48)0.95]O₃ ceramics, synthesized in pure perovskite phase by a solid-state reaction technique is investigated in the temperature range from 303 to 773 K by alternating-current impedance spectroscopy. Using Cole–Cole model, an analysis of the imaginary part of the dielectric permittivity with frequency is performed assuming a distribution of relaxation times. The scaling behavior of the imaginary part of the electric modulus suggests that the relaxation describes the same mechanism at various temperatures. The variation of dielectric constant with temperature is explained considering the space-charge polarization. The SEM indicates that the sample has single phase with an average grain size ∼14.2 μm. The material exhibits tetragonal structure. A detailed temperature dependent dielectric study at various frequencies has also been performed.