Electrical and Optical Properties of Ferroelectric Bi4Ti3O12 Single Crystals

Abstract

The symmetry of ferroelectric Bi4Ti3O12 is shown to be monoclinic point group m. The spontaneous polarization PS is approx 50 μC/cm2 at 25°C and lies in the monoclinic a-c plane at an angle of less than 5 deg from the plane of the crystal sheets. A complete determination of the optical indicatrix as a function of temperature is given. Switching for fields along the c axis occurs by a unique ``rocking'' of the large PS vector and leads to interesting electrical-optical behavior. The domain structure is quite complex, and observed wall orientations are compared with those predicted theoretically.