Doping effect and Zr/Ti control in the ferroelectric Pb(Zr,Ti)O3–SiO2 based glass–ceramic thin films derived by sol–gel method

Ferroelectric PbZrxTi1−xO3–SiO2 based glass–ceramic thin films were fabricated and characterized by sol–gel method. The perovskite-phase PbZrxTi1−xO3 (PZT) crystallites were grown in the films, preferentially along the (1 1 1) direction. Zr/Ti ratio in the PZT crystallites was found to decrease with increasing SiO2 concentration. The excess Pb addition did not decrease the Zr fraction in the PZT crystallites, whereas B added in the glass enhanced the Zr reduction in the PZT crystallites. The Zr/Ti ratio can be controlled to around the morphotropic phase boundary by using precursors with higher Zr concentration. The PbZr0.6Ti0.4O3–10 mol% SiO2–0.5 mol% B2O3 thin film showed the Zr/Ti ratio about 49/51 and good electric properties. Its dielectric constant and remnant polarization were higher than that of other PZT glass–ceramic films with the same amount of glass addition. The PZT glass–ceramic thin film is a suitable candidate for the integrated ferroelectric and piezoelectric devices.