Effect of Zr4+ on piezoelectric, dielectric and ferroelectric properties of barium calcium titanate lead-free ceramics

• Published in: Journal of advanced dielectrics 2021-12, Vol.11 (6)
• Main Authors: Panda, Prasanta Kumar, Sahoo, Benudhar, Sureshkumar, V., Politova, Ekaterina Dmitrievna
• Format: Article
• Language: English
• Subjects: Barium; Calcium titanate; Ceramics; Crystal lattices; Curie temperature; Diffraction patterns; Ferroelectricity; Grain size; Lead free; Low temperature; Pellets; Piezoelectricity; Polarization; Research Article; Room temperature; Sintering (powder metallurgy); Zirconium dioxide
• ISSN: 2010-135X; 2010-1368
• DOI: 10.1142/S2010135X21500247

Ba 0 . 8 5 Ca 0 . 1 5 ( Ti 1 − x Zr x ) O 3 (BCTZ) ceramics with x = 0.05, 0.10, 0.15, 0.20, 0.25, 0.30 were prepared by the solid-state reaction method. Calcination of the powders was carried out at 1100 ∘ C for 4 h and the green pellets were sintered at 1400 ∘ C for 2 h. X-ray diffraction patterns of the sintered pellets showed tetragonal splitting up to x = 0.10 while the mixture of the rhombohedral/cubic phase appeared at higher ZrO2 concentrations. Maximum piezoelectric charge constant d 3 3 = 510 pC/N and strain ( S = 0.103%) were measured for BCT doped by 0.10 mol ZrO2. Dielectric constant, remnant polarization and saturation polarization also found maxima for this composition. The Curie temperature ( T C ) of the compositions decreased with increase in ZrO2 concentration and reached 98 ∘ C, 87 ∘ C and 36 ∘ C at x = 0.05, 0.10, 0.15 mol, respectively. The remaining compositions have T C below the room temperature; therefore, they can be used for subzero/cryogenic applications. The scanning electron microscopy study revealed an increase in grain size with increase in ZrO2 concentration and confirmed the complete solubility of ZrO2 in the crystal lattice. Overall, low ZrO2-doped BCT compositions with high d 3 3 could be suitable for low temperature (