Dielectric relaxation behavior and electrical conduction mechanism in polymer-ceramic composites based on Sr modified Barium Zirconium Titanate ceramic

In this paper, we report the dielectric relaxation behavior and electrical conduction mechanism of Sr modified Barium Zirconium Titanate, (Ba_1-xSr_xZr_0.1Ti_0.9O₃ (x = 0.1, 0.2, 0.3)) (BSZT) ceramic in the polyvinyl alcohol (PVA) matrix. The single phase BSZT ceramics are prepared by the conventional solid state route and are added to the polymer matrix at 25:75 volume percentage. Surface morphology of polymer ceramic composite identifies the uniform distribution of the ceramic particles in the polymer matrix. Dielectric and tangent loss spectrum of the composites indicates the distribution of relaxation time. Electric modulus analysis shows the relaxation peaks of bulk and interface properties, which follows the Arrhenius law. The ac conductivity spectrum of pure PVA obeys Jonchers power law and polymer composites obey the double power law which conduction mechanisms are explained by Jump Relaxation Model. The activation energy varies from the relaxation to conduction mechanism indicates that the different charge contributions are involved in both the processes.