Crystal structures and ferroelectric properties of La-doped Bi4Ti3O12 crystals

La-doped Bi4Ti3O12 crystals are grown by a conventional flux method using Bi2O3 as a flux. The grown crystals exhibit plate-like morphologies and show only Bi4Ti3O12(00l) diffraction peaks. The remanent polarization P-r and the coercive field E-c of Bi4.3Ti3O12, Bi3.65La0.47Ti3O12 and Bi2.76La1.67Ti3O12 crystals are 3.2, 5.2 and 0.3 muC/cm(2), and 5.6, 7.6 and 0.6 kV/cm, respectively, under an applied field of about 16.5 kV/cm. However, Bi2.76La1.67Ti3O12 crystal seems to be not saturated. Bi4-xLaxTi3O12 crystals are tend to change from monoclinic to orthorhombic structure with increasing La concentration because those are substituted La for Bi with lone pair electron.