Electrical features of ferroelectric (BA0.83Ca0.17)TiO3 ceramics with diffused phase transition under pressure

Ferroelectric (Ba0.83Ca0.17)TiO3 ceramics was sintered by the solid state reaction method. The material was sintered in three steps that allowed remarkably modifying structure and electrical features important from an application point of view. Major tetragonal phase of the material was detected using X-ray diffraction study. The scanning electron microscope test showed fluctuation in chemical composition. The ferroelectric to paraelectric phase transition was diffused and markedly shifted to lower temperature, T-C = 339 K, respectively to barium titanate. Moreover, it showed the pressure sensitivity dT(C)/dp = -37 K/GPa. These effects were attributed to local disorder both in Ba/Ca and Ti sublattices. The high magnitude dielectric permittivity, epsilon'similar to 1000-2000, was observed in 200-400 K temperature range. The net polarization, which was estimated from the pyroelectric effect, decreased from similar to 3 mu C/cm(2) to zero in similar to 100-400 K range. The ceramics displayed the piezoelectric coefficient, d(33) = 58 pC/N, the spontaneous polarization, P-S = 11-14 mu C/cm(2), the remnant polarization, P-R similar to 2 mu C/cm(2), the coercive field, E-C similar to 1.5-3 kV/cm, and the energy density storage efficiency factor, xi approximate to 33%, at room temperature. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

Ferroelectric (Ba0.83Ca0.17)TiO3 ceramics were sintered by the solid state reaction method, which involved three steps to modify structure and electrical features, revealing tetragonal phase and fluctuation in chemical composition. The material exhibited pressure sensitivity and high dielectric permittivity, with varying polarization and piezoelectric properties within a certain temperature range.