In situ deposition of Pb(Zr0.25Ti0.75)O-3 thin films by RF magnetron sputtering has been performed at 500 degreesC on Pt/Ti/SiO2/Si substrates without any postannealing treatment. The growth of PZT is ensured, provided that a thin TiOx layer is sputtered prior to PZT. Moreover, we find that sputtering Ti in a 100% argon atmosphere leads to highly (100) oriented films, while adding oxygen during sputtering of Ti leads to purely (111) oriented films. Electrical measurements performed on these films show remanent polarization P-r, coercive field E-c, and dielectric constant consistent with their Zr/Ti ratio.