Dielectric behaviour of BZT-BCT nano pseudobinary system near TCP-assisted morphotopic phase boundary

• Published in: Ceramics international 2022-05, Vol.48 (9), p.12311-12316
• Main Authors: Mondal, R.A., Mishra, P., Parashar, S.K.S., Goswami, M.N.
• Format: Article
• Language: English
• Subjects: High energy ball milling; Hybrid Microwave sintering; Morphotropic phase boundary; Relaxation
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/j.ceramint.2022.01.093

The present study investigates the comparative dielectric studies in nano pseudobinary system synthesized by conventional and hybrid microwave sintering. The material was formed near Tri Critical Point (TCP)-assisted Morphotropic Phase Boundary (MPB) region from equal weight percentage of Lead Zirconate Titanate (BZT) and Barium Calcium Titanate (BCT) employing high energy ball milling. In the temperature dependent LCR study, a diffused phase transition (DPT) behaviour was identified for both conventional and hybrid microwave sintered samples. In each case, modified Currie-Weiss relation indicates an anomaly in the paraelectric state. Further, another approach using macroscopic composition-fluctuation model also exhibits the anomalous behaviour. Universal dielectric response (UDR) demonstrates that such behaviour is created by a temperature assisted relaxation phenomena by the formation of oxygen vacancies. Beyond 260 °C, microwave sintering creates more oxygen vacancies across grain boundary region as compared to the conventional sintering and in turn plays the key role for enhanced dielectric permittivity.