Effect of orientation on the dielectric and piezoelectric properties of 0.2Pb(Mg1/3Nb2/3)O-3-0.8Pb(Zr0.5Ti0.5)O-3 thin films

0.2Pb(Mg1/3Nb2/3)O-3-0.8Pb(Zr0.5Ti0.5)O-3 (0.2PMN-0.8PZT) thin films were d eposited on Pt(111)/Ti/SiO2/Si [Pt(111)] and Pt(200)/SiO2/Si [Pt(200)] subs trates by a sol-gel method, and the effect of orientation on the piezoelect ric and dielectric properties of 0.2PMN-0.8PZT thin films was investigated. The 0.2PMN-0.8PZT thin films on Pt(111) and Pt(200) showed strong (111) an d (100) preferred orientations, respectively. The spontaneous polarization of the (111) oriented film was higher than that of the (100) oriented film. However, the (100) oriented film showed a higher dielectric constant (K) a nd transverse piezoelectric coefficients (d(31)) than the (111) oriented fi lm. Because the spontaneous polarization direction of the (100) oriented fi lm is more tilted away from the normal to the film surface than that of the (111) oriented film, the dielectric constant and the transverse piezoelect ric coefficient (d(31)) of the (100) oriented film were enhanced. (C) 2001 American Institute of Physics.