FREQUENCY-DEPENDENT ELECTROMECHANICAL PROPERTIES FOR SOL-GEL DEPOSITED FERROELECTRIC LEAD-ZIRCONATE-TITANATE THIN-LAYERS - THICKNESS AND PROCESSING EFFECTS

The electromechanical properties of sol-gel-derived ferroelectric Pb(Z r0.53Ti0.47)O-3 (PZT 53/47) thin layers deposited on silicon were dete rmined as a function of field strength, measurement frequency, and tot al thickness. Both electrically induced strains (epsilon) and piezoele ctric properties (d(33)) were characterized by interferometry. Dielect ric spectroscopy and polarization switching (P-E) measurements were de termined for comparative purposes. An asymmetry between forward and th e reverse bias conditions in the E-E displacements was found for both five-layer deposited and nine-layer deposited structures. However, no asymmetry was observed in the P-E hysteresis characteristics. In addit ion, the electrically induced strains and the piezoelectric response w ere found to be dependent on measurement frequency. No significant fre quency dependence was observed in the polarization or dielectric respo nses. The results are discussed in terms of a possible clamping effect on polarization switching.