Glycolate tantalum based solutions for the sol-gel spin-coating depositionof SrBi2Ta2O9 thin films

The reaction of tantalum ethoxide with a glycol solvent produces the interc hange of the ethoxide groups with the glycol. As a result, a polymeric deri vative is formed with a high resistance towards hydrolysis. Compounds of Sr (II) and Bi(II) can be added to this Ta-glycol sol, leading to strontium bi smuth tantalate (SBT) precursor solutions stable in air. These solutions we re spin-coated onto two substrates: Pt/TiO2/SiO2/(100)Si and Ti/Pt/Ti/SiO2/ (100)Si. Crystallisation of the SET phase was carried out by a first format ion of a fluorite phase that evolves to the layered perovskite at temperatu res over 600 degreesC. During crystallisation, a larger tendency to the for mation of a substrate/film interface was observed in the films deposited on to Ti/Pt/Ti/SiO2/(100)Si than onto Pt/TiO2/SiO2/(100)Si, A remanent polaris ation of P-r>5 muC/cm(2) and a coercive field of E-c<100 kV/cm were measure d in the films on Pt/TiO2/SiO2/(100)Si. These films retain its remanent pol arisation, P-r, up to 10(5)seconds and are fatigue-free up to 10(9) cycles.