Electromechanical conversion efficiency of PZT films

PZT thin films have been prepared by opposed-target RF-sputtering and laser ablation. The titanium to zirconium ratios were 60/40 and 48/52. The latter films were doped with Fe and Sr (PZT 8). The dielectric constant, polarization, and d/sub 33/ coefficients were measured. A newly designed quadrature looper was used to acquire the polarization data and d/sub 33/ was measured with a stabilized interferometer. The dielectric properties ( epsilon and P) were slightly lower but comparable to bulk values. The best d/sub 33/ was 7.7 (for a 60/40 film). The d/sub 33/ value for the 48/52 RF-sputtered films was significantly lower than what one would expect from dielectric data. PZT films as-deposited are oriented and exhibit piezoelectric activity before any poling treatment. The material was also difficult to depole.<
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