Preparation of Pb(Zr,Ti)O3 thin films by sol gel processing: electrical, optical, and electro-optic properties

Crack-free transparent ferroelectric polycrystalline Pb(Zr,Ti)O3 thin films were prepared by spin-coating solutions of complex alkoxides. The preparation of stock solution, firing, and annealing of films was described. The coating of the intermediate layer of Al2O3 increased the adhesion between Pb(Zr,Ti)O3 thin films and glass substrates. The crystalline phases of films with varying Zr/Ti ratios were investigated. The dielectric constants were about 260. The remanent polarization and coercive field were 6.6 μC/cm2 and 26.7 kV/cm, respectively. The refractive index of the perovskite Pb(Zr,Ti)O3 films was 2.6 at 6328 Å, and the absorption edge was at 3400 Å. The quadratic and linear electro-optic effects were measured with respect to the Zr/Ti ratio from 40/60 to 60/40 for films grown on glass substrates. The quadratic and linear electro-optic coefficients were about 1×10−18 m2 /V2 and 2.4×10−11 m/V at 6328 Å, respectively.