Proposal of New Electromechanical Poling Treatment for Barium Titanate Single Crystals

Abstract

The phase transition behaviors of the [111] oriented barium titanate (BaTiO3) single crystals were investigated as functions of temperature, uniaxial stress and electric fields. For the phase transition by temperature, with decreasing temperature above Tc, the paraelectric phase changed to the intermediate phase with superparaelectric state, and finally change to the ferroelectric phase with randomly oriented spontaneous polarizations. Moreover, it was also found that the phase transition by uniaxial stress field above Tc was almost similar one by temperature. On the other hand, for the phase transition by electric field above Tc, with increasing electric field, the paraelectric phase changed to the intermediate phase, and finally changed to the ferroelectric phase with the oriented polar direction. These results suggested that above Tc, combination between uniaxial stress and electric fields might be effective for a poling treatment of BaTiO3 crystals. Thus, in this study, a new poling method for the BaTiO3 crystals was proposed using control of temperature, uniaxial stress and electric fields.