Piezoelectric properties of PZT thin films on metallic substrates

Abstract

The piezoelectric properties of PZT thin films on metallic substrates prepared by sol-gel processing were investigated. The films show a high remanent polarization of about 40 μC/cm2 and a coercive field strength of about 10 V/μm. The direct piezoelectric effect was used for measuring the electrical charge generated by an applied strain. The generated charge depends linearly on the strain up to a strain of about 0.1 %. A charge per area of about 0.1 μC/cm2 was measured for a strain of 0.1 %. From these measurements the piezomodulus d31 was calculated. The values of d31 were about 29 pC/N and have been compared with former measurements of the piezomodulus d33. The time dependence and the mechanical fatigue of the piezomodulus were investigated. The piezomoduli remain nearly constant up to 105 mechanical or electrical cycles, after this the piezomoduli decrease.