Net spontaneous polarisation in As-grown SET films

SrBi2Ta2O9 ferroelectric thin films have been deposited by metalorganic dec omposition (MOD) on Pt/TiO2/SiO2/(100)Si substrates. Crystallisation of the spun-on films was carried out under O-2 flow, at temperatures of 750 degre esC for times that ranged from 10 to 60 minutes. The resulting 300 nm thick films were orthorhombic single phase and random or slightly < 100 >/< 010 > oriented, as determined by XRD. A relative strong net polarisation, in co mparison with the available switched value, has been measured by a novel me thod used to trace the first hysteresis loop. Remnant polarisation values, Pr congruent to 5 9 muC/cm(2), and leakage current densities below 10(-7) A /cm(2) at 3 V have been obtained. No significant fatigue was observed after 10(10) write/read cycles and P-r was retained for up to 10(5) s. Results a re discussed on the basis of the films texture and microstructure. Net pola risation results indicate that only switching of 180 degrees domains occurs , taking into account that the polar direction lies along the a-axis.