Investigation of dielectric relaxor-like anomaly behaviour of non-ferroelectric BaZrO3 polycrystalline ceramic

• Published in: Materials science & engineering. B, Solid-state materials for advanced technology Solid-state materials for advanced technology, 2023-09, Vol.295, p.116603, Article 116603
• Main Authors: Saini, Deepash Shekhar, Kumar, Sandeep, Yadav, Sesh Mani, Kumar, Manindra, Ghosh, Avijit
• Format: Article
• Language: English
• Subjects: Barium zirconate; Colossal dielectric constant; Ferroelectric phase-transition; Jonscher’s power law; Maxwell-Wagner relaxation; Relaxor-like anomalies
• ISSN: 0921-5107; 1873-4944
• DOI: 10.1016/j.mseb.2023.116603

[Display omitted] •The colossal dielectric behaviour was detected in the dielectric spectra in accompanying with two relaxor-like anomalies in BaZrO3 ceramic.•The bulk and Maxwell-Wagner relaxation phenomena are responsible for the oxygen-vacancy induced pseudo-relaxor behaviour.•The dielectric anomaly at 585 °C is due to ferroelectric phase transition induced by the disordered to ordered state of oxygen vacancies. The dielectric responses and ac conductivity of non-ferroelectric BaZrO3 polycrystalline ceramic were examined in the wide ranges of frequency and temperature. The colossal dielectric behaviour was detected in the dielectric spectra, accompanied by two relaxor-like anomalies. The activation energy associated with the relaxor behaviour at low temperature regions was estimated to be 0.85 eV. The bulk relaxation and Maxwell-Wagner relaxation effect are responsible for the oxygen-vacancy induced pseudo-relaxor behaviour at low-temperature dielectric anomalies. The dielectric anomaly at 585 °C was confirmed to be a paraelectric to ferroelectric phase transition induced by the process of disordered to ordered state of oxygen vacancies. A modified empirical Cole-Cole model was proposed to explain the frequency-dependent permittivity and dielectric loss spectra. The two humps at low and high-temperature regions associated with oxygen-vacancy induced pseudo-relaxor and paraelectric to the ferroelectric phase transition, respectively, were observed in the temperature-dependent ac conductivity study.