Investigation of the BaTiO3–BaMg1/3Nb2/3O3 system: Structural, dielectric, ferroelectric and electromechanical studies
Lead-free (1−x) BaTiO3 –x BaMg1/3Nb2/3O3 ceramics with x = 0.03, 0.04, 0.05 and 0.06 were prepared by solid-state synthesis. The effects of the Ba(Mg1/3Nb2/3)O3 addition on the phase composition, dielectric and ferroelectric properties, as well as the electromechanical response of the classic ferroelectric BaTiO3 were investigated. The room-temperature X-ray diffraction analyses of all the ceramics revealed a perovskite phase after sintering at 1300 °C with a composition-dependent symmetry. The samples with a lower concentration of Ba(Mg1/3Nb2/3)O3, i.e., x = 0.03 and 0.04, were tetragonal, while the samples with x = 0.05 and 0.06 were found to be cubic. The result is in agreement with the dielectric, ferroelectric and electromechanical properties. With x increasing from 0.03 to 0.06 the temperature of the diffused maximum of the dielectric permittivity decreased from 348 K to 265 K. All the ceramics showed a large electromechanical response: the calculated room-temperature electrostrictive coefficient M 33 of the sample with x = 0.06 was 1.4 · 10−16 m2/V2, which is comparable to the value measured for Pb(Mg1/3Nb2/3)O3 ceramics.
KeywordsX-ray Dielectric Ferroelectric Ceramics Perovskite Lead-free
One of the authors (B. N.) wishes to express his sincere thanks to the Nuclear Research Centre of Birine for the financial support through a research grant and to the Electronic Ceramics Department of Jožef Stefan Institute for the use of their facilities.
G. T., S. G. and M. K. are grateful to the Slovenian Research Agency (Program No. P2-0105) for its financial support. These authors would also like to thank Dr. Jan Petzelt and Prof. Zdravko Kutnjak for their fruitful discussions.
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