Frequency-dependent electromechanical properties for sol-gel deposited ferroelectric lead zirconate titanate thin layers: Thickness and processing effects

Abstract

The electromechanical properties of sol-gel-derived ferroelectric Pb(Zr_0.53Ti_0.47)O₃ (PZT 53/47) thin layers deposited on silicon were determined as a function of field strength, measurement frequency, and total thickness. Both electrically induced strains (∊) and piezoelectric properties (d₃₃) were characterized by interferometry. Dielectric spectroscopy and polarization switching (P-E) measurements were determined for comparative purposes. An asymmetry between forward and the reverse bias conditions in the ∊-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 addition, the electrically induced strains and the piezoelectric response were found to be dependent on measurement frequency. No significant frequency dependence was observed in the polarization or dielectric responses. The results are discussed in terms of a possible clamping effect on polarization switching.