The effects of oxygen partial pressure during deposition and V and P doping on the microstructures and ferroelectricity of sputterdeposited Bi3.25La0.75Ti3O12 (BLT) films on Pt/SiO2/Si(100) were studied. At the deposition pressure of 4 mTorr the O-2/(Ar+O-2) ratio in the range of 0.4-0.5 allowed the films to achieve a larger remnant polarization (2P(r)). For the (Bi3.25La0.75)(Ti3-xVx)O-12 films, the 2P(r) first increases with increasing the V concentration (x) up to 0.03, then gradually decreases in the range of x=0.05-0.1 and drastically decreases at x=0.15. The doping of V into the BLT films can simultaneously induce two contrary effects on the 2P(x), i.e., reducing the amount of oxygen vacancies and decreasing the grain size, which result in the improvement and degradation of 2(Pr), respectively. The two effects are similar to those induced by the factor of oxygen partial pressure during deposition. The degradation of 2P(x) for the P-doped BLT films can be ascribed to the dissociation of Bi-O bonds and reduction of grain size due to P doping. (C) 2004 Elsevier B.V. All rights reserved.