Sol-gel deposition of PZT thin films on ceramic ZrO2 substrates
Pb(Zr1–xTix)O3 thin films (x = 0.55 and 0.85) were prepared on fine grained, polished ZrO2 ceramic substrates by a sol-gel method. The high thermal expansion of ZrO2 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: Pr = 36 µC/Cm2, and Ec = 45 kV/cm, at a field of 160 kV/cm. Pyroelectric figures of merit, defined as P/eps, of 0.93 were measured for a 4.0 µm thick Pb(Zr0.15Ti0.85)O3 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.