%0 Journal Article %K Thin films %K Substrates %K Epitaxial growth %K Single crystals %K Piezoelectricity %K Crystal symmetry %K Lead compounds %K Epitaxial films %K Polycrystalline materials %K Converse longitudinal piezoelectric constants %K Rhombohedral structure %K Tetragonal structure %K Elastic moduli %A J Ouyang %A Ramamoorthy Ramesh %A A.L Roytburd %B Advanced Engineering Materials %D 2005 %G eng %P 229-232 %R 10.1002/adem.200400214 %T Theoretical predictions for the intrinsic converse longitudinal piezoelectric constants of lead zirconate titanate epitaxial films %V 7 %X The intrinsic converse longitudinal piezoelectric constants of lead zirconate titanate (PZT) epitaxial films were calculated. The calculation results show that both tetragonal and rhombohedral PZT films have similar orientation dependence as those of their bulk materials. It was observed that in films with a rhombohedral structure, d 33,f values are much more reduced in non-polar directions than in the polar direction [111], as compared with the bulk properties. It was found that substrate clamping can vary these constants and gives numerical results for PZT films with various composition.