Effect of incorporating nonlanthanoidal indium on the ferroelectric performance of Bi4Ti3O12 thin films

Nonlanthanoid-substituted In-x-Bi4Ti3O12 films with different indium contents at x=0, 0.2, 0.4, and 0.5, based upon the chemical formula of (Bi4-xInx)Ti3O12, were prepared at 600 degrees C by chemical solution deposition. In-0.4-Bi4Ti3O12 films displayed a large remanent polarization of 57 mu C/cm(2), coercive field of 100 KV/cm, high nonvolatile polarization >= 30 mu C/cm(2) after 10(10) switching cycles, and low annealing temperature of 600 degrees C. Good ferroelectric properties are mainly attributed to the partial substitution of the smaller-sized Ti4+ site by the larger-sized In3+ to enhance electrical polarization by a dimensional change of unit cell and to provide fatigue resistance by lattice distortion and chemical stabilization. (c) 2006 American Institute of Physics.