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(Mg-1/3,Nb-2/3)O-3-xPbTiO(3) (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 degrees 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. (C) 2009 Elsevier Inc. All rights reserved.