Effect of sintering condition and V-doping on the piezoelectric properties of BaTiO₃–Bi(Mg_1/2Ti_1/2)O₃–BiFeO₃ ceramics

Abstract

0.3BaTiO 3 0.1Bi(Mg 1/2 Ti 1/2 )O 3 0.6BiFeO 3 ceramics were either doped with vanadium or sintered in calcined powder with the same composition. Compared to an undoped ceramic sintered without the calcined powder, both ceramics showed reduced leakage current densities (lower than 1 © 10 ¹7 A/cm 2 ) and absence of dielectric relaxation behaviors observed in frequency-and temperature-dependent dielectric measurements. The Curie temperatures of both samples were higher than 460°C. The maximum field-induced strain over the applied field, S max /E max , of 366 pm/V for the undoped ceramic sintered without the calcined powder increased to 455 and 799 pm/V for the V-doped sample and the sample sintered with the calcined powder, respectively. The increase was discussed with reduced concentrations of bismuth vacancyoxygen vacancy defect dipoles.

Large Electric-field-induced Strain in Pseudo-cubic BaTiO₃-Bi(Mg_0.5Ti_0.5)O₃-BiFeO₃ Ceramics

“…The laboratory XRD measurements confirmed that both samples consisted of a single perovskite phase and the crystal system was a pseudo-cubic. The results agreed with previous studies [7] [18]. The density of both ceramics prepared from the powders A and B was 97-98% of the theoretical value.…”

“…4. For both samples, ferroelectric P-E loops were observed, which was consistent to previous studies [7][18] [19]. The P-E loop of the ceramics prepared from the powder A appeared lossy due to the lower resistivity.…”

“…X-ray diffraction (XRD) analyses showed that the phase boundary between a rhombohedral phase and a pseudo-cubic phase existed between 0.2BT-0.1BMT-0.7BF and 0.3BT-0.1BMT-0.6BF. A maximized electric-field induced strain was observed near the phase boundary of the pseudo-cubic 0.3BT-0.1BMT-0.6BF composition having a nanodomain structure, with the strain maximum/ the applied electric field amplitude of 799 pm/V (E max = 50 kV/cm) for the ceramics sintered with care of minimizing bismuth volatilization [7]. Interestingly, a well-developed ferroelectric polarization electric field (P-E) loop was observed for the pseudo-cubic composition, which suggested the pseudo-cubic phase was changed to a ferroelectric phase with a lower symmetry by application of the electric field.…”

Solid-solution thin films of ternary BaTiO3–Bi(Mg1/2Ti1/2)O3–BiFeO3system epitaxially grown on SrRuO3//SrTiO3substrates via chemical solution process

“…The ternary solid-solution system of BaTiO 3 -Bi(Mg 1=2 -Ti 1=2 )O 3 -BiFeO 3 (BT-BMT-BF) is one candidate Pb-free material that can exhibit excellent spontaneous polarization (P s ) and piezoelectric response. [1][2][3][4][5] An important issue is its phase transition behavior; the crystallographic symmetry of the perovskite unit cell varies with the chemical composition. In particular, the composition of 0.3BT-0.1BMT-0.6BF is located near the phase boundary between the BF-rich rhombohedral phase and the intermediate pseudocubic phase neighboring the BT-rich tetragonal phase.…”