Ferroelectric 0.7Pb(Mg1/3Nb2/3)O-3-0.3PbTiO(3) (PMN-PT) thin films were deposited on ZrO2/SiO2/silicon substrates using a chemical-solution-deposition method. Using a thin PZT film as a seed layer for the PMN-PT films, phase-pure perovskite PMN-PT could be obtained via rapid thermal annealing at 750degreesC for 60 s. The electrical properties of in-plane polarized thin films were characterized using interdigitated electrode arrays on the film surface. Ferroelectric hysteresis loops are observed with much larger remanent polarizations (similar to24 muC/cm(2)) than for through-the-thickness polarized PMN-PT thin films (10-12 muC/cm(2)) deposited on Pt/Ti/Si substrates. For a finger spacing of 20 mum, the piezoelectric voltage sensitivity of in-plane polarized PMN-PT thin films was similar to20 times higher than that of through-the-thickness polarized PMN-PT thin films.