Structure and electrical properties of lanthanum-doped CaBi4Ti4O15-Bi4Ti3O12 intergrowth ferroelectric

Structure and electrical properties of lanthanum-doped CaBi4Ti4O15-Bi4Ti3O12 (CaBi(8-x)LaxTi7O27, CBT-BIT-xLa) intergrowth ferroelectric were studied. With increasing the La3+ content, CBT-BIT-xLa showed increased lattice parameters and decreased grain sizes. The total La3+ content in BIT part is similar to that in CBT part. The dielectric loss was decreased with La3+ doping. Both remnant polarization (2P(r)) and the coercive electric field (E-c) increase with increasing La3+ content at 0.0 <= x <= 0.4, show maximum values of 24.5 mu C/cm(2) and 60.8 kV/cm with x=0.4, and decrease when x >= 0.4. Meanwhile, the piezoelectric constant (d(33)) increases as the doping level of La3+ increases from 0.0 to 0.8, gets a maximum value of 23.4 pC/N at x=0.8, and then decreases. (C) 2015 Elsevier B.V. All rights reserved.