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Microstructural Features and Functional Properties of Bilayered BaTiO 3 /BaTi 1− x Zr x O 3 Ceramics
Author(s) -
Amaral Thiago Martins,
Antonelli Eduardo,
Ochoa Diego Alejandro,
García José Eduardo,
Hernandes Antonio Carlos
Publication year - 2015
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.13417
Subject(s) - materials science , microstructure , ceramic , dielectric , permittivity , composite material , ferroelectricity , pyroelectricity , piezoelectricity , sintering , mineralogy , optoelectronics , chemistry
Validity of mixture rule for dielectrics in series configuration and the correlation between microstructure and electrical properties in bilayered BaTiO 3 /BaTi 1− x Zr x O 3 ceramics were studied. Samples were obtained from BaTi 1− x Zr x O 3 ( BTZ x ) nanopowder synthesized by the polymeric precursor technique and had their microstructure, dielectric, piezoelectric, and ferroelectric properties investigated. These bilayered ceramics' properties were compared to the properties of homogeneous BTZ x samples. And, also, the formers' electrical permittivities were compared with the predictions of the simple mixture rule. According to the results, the microstructures of the layers do not differ from the microstructure of the corresponding homogeneous BTZ x ceramic. And pyroelectric coefficient measurements show that the electrical properties of the interface do not contribute to the functional properties of the bilayered samples. Nevertheless, on increasing Zr 4+ , the agreement between the experimental and the predicted permittivity of the bilayered ceramics is gradually reduced, mainly at temperatures where the permittivity is governed by the response of the layer containing Zr 4+ . As a mechanical joint between the layers, the interface induces stresses during sintering due to thermal mismatch between compositions, thereby affecting the bilayers' electrical properties. Our results show that interface's mechanical effects compromise the functional properties of layered ferroelectric ceramics.