Sol gel processing of thick PZT films

Techniques are described for the sol-gel fabrication of ferroelectric PZT (lead zirconate titanate) films on different substrates up to 1.5 μm in thickness by a single coating and up to 8 μm by multiple coating. A microscopic and macroscopic review of the sources of stress in films during drying and firing suggests procedures for fabricating thick PZT films. These include the use of additives such as glycerol to reduce internal stress during firing, and appropriate firing schedules to accommodate the film thickness. A mechanical model for guiding the development of such films is presented