PRECURSOR-MONOMER METHOD OF SOL-GEL FOR FABRICATION PT/PZT/PT FERROELECTRIC FILMS

ABSTRACT

Lead zirconate titanate Pb(Zr_0.52Ti_0.48)O₃ (PZT) thin films was successfully deposited on Pt(111)/Ti/SiO₂/Si(100) substrates by a new modified sol-gel technique: precursor-monomer method. In this process three separated Pb^{2 +}, Zr^{4 +}, Ti^{4 +} precursor-monomers and metal chelating agents were mixed together to prepare PZT sol-solution (precursor). The precursor-monomer method has several advantages over conventional sol-gel methods, including easy change the atomic ratio of Pb^{2 +}/Zr^{4 +}/Ti^{4 +} and doping metallic ions, rapid PZT precursor synthesis, low processing temperature, without dry condition and distillation, long storage period, simplicity and low cost, etc. The paper investigated the effects of hydrolysis degree on the stability of PZT precursor, and it was found that the sample with 12.5% (v/v) adding water had the longest storage time. The inference of lead titanate (PbTiO₃, PT) seeding layers on the microstructures, surface morphologies and ferroelectric properties of PZT films has also been systematically examined. We found that PZT films with PT/PZT/PT structure had lower perovskite phase crystallization temperature, larger grain size, better microstructure and ferroelectric properties as compared with no PT seeding layers films.

Keywords:

• PZT
• sol-gel
• precursor-monomer
• ferroelectric film