The piezoelectric and dielectric constants for Pb(Mg1/3Nb2/3)O3-PbTiO3(PMN-PT, 70/30) films with different orientations were measured. PMN-PT films were deposited on Pt(111)-passivated silicon substrates using a modified sol-gel process. The room temperature dielectric constants K for the (100)-oriented films were 2500-2600, while K for (111)-oriented films were 1900-2000. In both cases tan δ was less than 0.03. The dependence of the piezoelectric coefficient d31of the PMN-PT films on the poling fields was investigated. The d31coefficients of (100)-oriented PMN-PT films were found to range from -28 to -69 pC/N with poling field. The (100)-oriented PMN-PT films showed larger piezoelectric coefficient than (111)-oriented films. The d33coefficients of the 1.5 μm thick (100) oriented PMN-PT films were ∼170-183 pC/N. The aging rate of -d31was ∼4%-10%/decade.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)