EFFECTS OF PARTICLE-SIZE ON THE PHASE-TRANSITION IN PB(ZR, TI)O-3 GROWN BY THE SOL-GEL TECHNIQUE

The variation of the tetragonal distortion (c/a) with particle size of Pb(Zr, Ti)O-3 nanoparticle thin films prepared by the sol-gel techniq ue is reported. The tetragonal distortion of the unit cell, which is r elated to the spontaneous polarization, decreases exponentially with s ize and vanishes at 16 nm. This distortion was correlated with the use d additive in the preparation processing and crystallization temperatu re of the films, and the existence of a critical groin size for the fe rroelectric phase transition was observed. The phase transition was mo nitored by X-ray diffraction, scanning electron microscopy, and electr ical measurements. (C) 1998 Elsevier Science B.V.