ENHANCED THERMODYNAMIC STABILITY OF TETRAGONAL-PHASE FIELD IN EPITAXIAL PB(ZR,TI)O-3 THIN-FILMS UNDER A 2-DIMENSIONAL COMPRESSIVE STRESS

A two-dimensional thermodynamic model was developed to account for the observed difficulty in the fabrication of epitaxial Pb(Zr,Ti)O-3 (PZT ) thin films in which tetragonal and rhombohedral phases coexist. The thermodynamic formalism based on the Landau-Devonshire's phenomenologi cal theory predicts the enhanced thermodynamic stability of the tetrag onal-phase field under a two-dimensional compressive stress. We have e xperimentally proved this prediction by fabricating an epitaxially ori ented tetragonal PZT thin film on MgO substrate with the target compos ition corresponding to the bulk morphotropic phase boundary (MPB). (C) 1998 American Institute of Physics.