Sol-gel deposition of PZT thin films on ceramic ZrO/sub 2/ substrates

Pb(Zr/sub 1-x/Ti/sub x/)O/sub 3/ thin films (x=0.55 and 0.85) were prepared on fine grained, polished ZrO/sub 2/ ceramic substrates by a sol-gel method. The high thermal expansion of ZrO/sub 2/ relative to Si allows the preparation of thicker PZT films with reduced thermal stress. For the x=0.85 films, this reduction of thermal stress gives a preference of [001] over (100) oriented domains. For x=0.55 films, square P-E hysteresis loops were obtained with: P/sub r/=36 /spl mu/C/cm/sup 2/, and E/sub c/=45 kV/cm, at a field of 160 kV/cm. Pyroelectric figures of merit, defined as P//spl epsi/, of 0.93 were measured for a 4.0 /spl mu/m thick Pb(Zr/sub 0.15/Ti/sub 0.85/)O/sub 3/ film. The measured properties were comparable to those of highly (111) oriented films on Si. Thus, the [001] texture must be increased in order to realize improved properties.