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

抄録

Pseudo-cubic 0.3BaTiO₃-0.1Bi(Mg_0.5Ti_0.5)O₃-0.6BiFeO₃ ceramics with a high electric resistivity were prepared via a low-temperature powder synthesis and the ceramics were used for synchrotron X-ray diffraction measurements conducted under electric fields of 0 – 50 kV/cm to understand their ferroelectric polarization – electric field (P-E) response. The XRD measurements showed no diffraction peak splitting while changes in the intensities of peaks as the electric fields applied, which suggested that the ferroelectric P-E response was not caused by an electric-field-induced phase transition from the pseudo-cubic phase to a ferroelectric phase, but probably caused by domain switching in nanodomains. The lattice spacings of the ceramics increased along the electric field (33-directon) and contracted in the direction normal to the electric field (31-direction). The piezoelectric constant calculated from the peak shift of the 200 peak was 960 and −260 pm/V in the 33- and 31-directions, respectively.