Preparation and Ferroelectric Properties of Lanthanum Modified Sr0.8Bi2.2Ta2O9 Thin Films

La modified Sr_0.8Bi_2.2Ta₂O₉ (SLBT) thin films were fabricated on Pt/Ti/SiO₂/Si substrates by metalorganic decomposition. All the films were annealed at 800°C using a rapid thermal annealing furnace. X-ray diffraction analysis indicated that single-phase layered perovskite SLBT ferroelectric thin films can be obtained and no secondary phase was found. The crystallization and hysteresis behavior of SLBT films showed a dependence on the La content. An increase of P_r and decrease of E_c with increasing La concentration were observed. The fatigue properties were found to be improved when more La was added to SLBT films. The results were discussed with respect to the effects of La³⁺ and Bi³⁺ substitution at perovskite A-site.