Synthesis and characterization of ferroelectric Nb-doped PZT thin films

This thesis deals with the processing and characterization of Nb-doped Lead Zirconate Titanate (PNZT) sol-gel films. First of all, a new route to synthesize stable and homogeneous sol-gel precursors solutions has been developed. Lead(II) acetate trihydrate (Pb(CH3CO2)2 •3H2O, Niobium(V) ethoxide (C10H25NbO5), Zirconium propoxide Zr(OCH2CH2CH3)4 (70 wt% in propanol) and Titanium isopropoxide [Ti ((CH3)2CHO)4] are used as precursors materials and acetic acid and propanol as solvents. Four different solutions have been prepared varying the Nb composition. For each kind of solution, a proper thermal treatment has been defined to obtain dense, uniform and cracks free PZT films that possess a fully perovskite crystallographic structure. The films morphology has been analyzed using SEM and optical microscope and the crystallographic structure has been studied using grazing incident X-ray diffraction The electrical features of these films have been analyzed calculating the C-V and the ε-V curves, from which the ferroelectric behavior of these films has been confirmed