Grain boundary-modified dielectric spectra of electroceramics: the occurrence of 'unexpected' thermal dielectric loss peaks

• Published in: Physica status solidi. B. Basic research Vol. 244; no. 9; pp. 3390 - 3397
• Main Authors: Antonelli, Eduardo, M'Peko, Jean-Claude, Hernandes, Antonio Carlos
• Format: Journal Article
• Language: English
• Published: Berlin WILEY-VCH Verlag 01.09.2007; WILEY‐VCH Verlag; Wiley
• Subjects: 77.22.Ch; 77.22.Gm; 81.05.Je; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Dielectric loss and relaxation; Dielectric properties of solids and liquids; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Exact sciences and technology; Physics; Grain boundaries; Frequency dependence; Barium Zirconates; Capacitors; Dielectric losses; Anomaly; Electroceramics
• ISSN: 0370-1972; 1521-3951
• DOI: 10.1002/pssb.200642412

Manifestation of dielectric/magnetic anomalies is often used to postulate or corroborate occurrence of structural phase transitions in both single‐crystal and polycrystalline materials. In the latter case, furthermore, some important aspects of grain‐boundary influence on the overall electrical response of materials have been more or less extensively characterized elsewhere. Nevertheless, the possible occurrence of ‘anomalous' thermal dielectric loss peaks, not associated with phase transitions or any other potential source, but still arising from grain boundary‐induced effects, has been less considered and explored. Here, BaZrO3 ceramics, commonly proposed to be attractive in the capacitor industry, are found to qualitatively and quantitatively help discussing and approaching this question by measuring, deeply treating and analyzing fixed‐frequency and frequency‐dependent impedance data. The overall work shows that grain boundary‐induced thermal dielectric peaks may occur, with temperature locations that may also be reasonably predicted. © 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim