abstract
Polycrystalline sample of lead-free 0.5Ba(Zr0.2Ti0.8)O-3-0.5(Ba0.7Ca0.3)TiO3 ceramic has been synthesized by solid state reaction method. Single-phase perovskite structure with rhombohedral symmetry was confirmed by x-ray diffraction. Temperature dependent dielectric permittivity studies demonstrated frequency independent behavior, indicating that the studied sample was not a typical relaxor ferroelectric. A polymorphic phase transition between rhombohedral and tetragonal phase was noticed near room temperature followed by a tetragonal to cubic transition with 97 degrees C as the temperature of maximum permittivity. The macroscopic values of d(33) and d(31) were similar to 350 pC/N and -141 pm/V, whereas the electromechanical coupling factors k(p) and k(t) were 44.5% and 41.6%, respectively. Bulk P-E hysteresis loop was obtained with saturation polarization 11 mu C/cm(2) and coercive field similar to 4 kV/cm. Distinct polarization contrast with a complex mosaic-like domain structure was observed in the out-of-plane mode of piezoresponse force microscopy. The domain width and the correlation length were estimated to be nearly 2 mu m and 827 nm, respectively. Local hysteresis loop with apparent coercive voltage, V-c = 15.8 V, was observed. (C) 2013 AIP Publishing LLC.
keywords
FREE PIEZOELECTRIC CERAMICS; DIFFUSE PHASE-TRANSITION; FERROELECTRIC CERAMICS; FREE PIEZOCERAMICS; TEMPERATURE; RELAXOR; PIEZORESPONSE; POLARIZATION; CONSTANTS; TITANATE
subject category
Physics
authors
Coondoo, I; Panwar, N; Amorin, H; Alguero, M; Kholkin, AL
our authors
Andrei Kholkin
Retired Researcher
Indrani Coondoo
Junior Researcher
Neeraj Panwar
Post-doc FellowshipGroups
G2 - Photonic, Electronic and Magnetic Materials
G3 - Electrochemical Materials, Interfaces and Coatings
acknowledgements
The authors I. C. and N.P. would like to thank the Portuguese Foundation for Science and Technology (FCT) for the Postdoctoral grants through Project Nos. SFRH/BPD/81032/2011 and SFRH/BPD/71289/2010, respectively. Financial support by Spanish MICINN Project MAT2011-23709 is also acknowledged.