Sol-gel derived PZT/RuO2 multilayer films on stainless steel substrates

The structural and electric properties of PZT thin films deposited by the sol-gel process on RuO2 coated stainless steel as well as on bare stainless steel were studied and compared. As-deposited amorphous RuO2 thin films on stainless steel were transformed to pure rutile-type RuO2 at temperatures ranging from 400 degrees C to 600 degrees C, the resistivity of which had a value less than 200 mu Ohm . cm. The PZT films processed on RuO2 needed slightly higher temperature (610 degrees C) in order to be completely transformed into the perovskite phase than PZT on stainless steel (600 degrees C). The films showed best ferroelectric properties when depositing it on the 100 nm thick RuO2 bottom electrodes fired at 400 degrees C for 10 minutes. The hysteresis loops of the PZT films were more slim when being processed on RuO2 coated stainless steel than on bare stainless steel. For the RuO2 bottom electrodes the values of coercive field decreased to about 55% of those without a RuO2 layer.