Direct crystallization of perovskite phase in PMN–PT thin films prepared by polyvinylpyrrolidone modified sol–gel processing and their properties

A modified sol–gel processing has been developed by using polyvinylpyrrolidone (PVP) as modifier and lead nitrate as lead source to synthesize (1−x)Pb(Mg1/3,Nb2/3)O3–xPbTiO3 (PMN–PT) thin films with x=0.23–0.43. With PVP additions, perovskite phase could directly crystallize from amorphous films at the temperature as low as 430 °C via bypassing the metastable phase-pyrochlore and crystallinity was significantly enhanced. The PVP addictives have been optimized with molecular weight <630 K and the ratio of PVP monomer/PMN–PT at 0.25–1.0. XPS analysis indicates that the chemical states of the elements in the well-crystallized PMN–PT films are close to the literature data for the PMN–PT single crystals and the films possess highly desired electrical and optical properties.