SrBi2Nb2O9 Ferroelectric Powders and Thin Films Prepared by Sol-Gel

Pure SrBi2Nb2O9 powders and thin films were obtained using sol-gel synthesis from mixtures of niobium ethoxide, bismuth and strontium 2-ethylhexanoates. Powders crystallized for 2 hours at 700°C had grain sizes of about 100–150 nm. SrBi2Nb2O9 thin films were prepared by spin-coating a stable precursor solution onto Si/SiO2/TiO2/Pt substrates. Crystallization of pure SrBi2Nb2O9 phase occurred at about 500–550°C. Randomly oriented 0.3 μm-thick crack-free films were obtained after 10 successive depositions and heating at 700°C for 2 hours. P-E hysteresis loops have confirmed the ferroelectric behavior of the films: they show a remanent polarization of 2.5 μC/cm2 (5 V, 8 ms). No fatigue was observed up to 109 full switchings.