Diffuse phase ferroelectric vs. Polomska transition in (1-x) BiFeO3-(x) Ba Zr0.025Ti0.975O3 (0.1 ≤ x ≤ 0.3) solid solutions

Investigations on the solid solutions (1-x) BiFeO3 - (x) Ba Zr0.025Ti0.975O3 (0.1 <= x <= 0.3) in the temperature range 300-750K show colossal permittivity behavior and the occurrence of diffuse phase ferroelectric transition along with frequency dependent anomaly which disappears at temperature similar to 450 K. For x = 0.3, these anomalies have been verified through differential scanning calorimetry and dielectric/impedance/conductivity measurements. The occurrence of peak in pyrocurrent (dP(s)/dT) vs. T plots also supports phase transition. With the increasing x, transition temperature decreases and diffusivity increases. This anomaly is absent at high frequencies (>100 kHz) in conductivity plots, indicating Polomska like surface phase transition, which is supported by modulus study. (C) 2015 AIP Publishing LLC.