Processing and thickness effects on the microstructure and electrical properties of sol-gel deposited Pb(Zr, Ti)O3 films

Conventional and modified sol-gel processes were used to deposit PZT films with different thicknesses and Zr:Ti ratio on Pt/Ti/SiO2/Si substrates. The crystalline structure and growth behavior of the films have been studied by X-ray diffraction, scanning electron microscopy, and Auger electron spectroscopy. The ferroelectric polarization-electric (P-E) hysteresis loops of the films was also measured and discussed. The structure of piezoelectric element is as (Au or Pt/Ti)/PZT/Pt/Ti multilayer film. Meanwhile, it has a relatively flat surface and each layer exhibits a very dense, uniform, sharp interface. According to the results of P-E hysteresis loops, for given PZT film, the polarization and coercive electric field increase with applied voltage increasing. Furthermore, a new piezoelectric micro-actuator including two PZT elements and a U-type stainless steel substrate for positioning a magnetic head in a high-density hard disc device has been fabricated and investigated. The micro-actuator was also tested in order to investigate the driving mechanics. The results show that the peak-to-peak head displacement of 1.146 μm is achieved when an alternating voltage of ±20 V is applied on a U-type micro-actuator bonding with two 3 μm thick PZT elements and experimental frequency response of the micro-actuator with HSA higher than 22 kHz, yielding the required servo bandwidth (13 kHz).