SrBi₂Nb₂O₉ ferroelectric thin films

Abstract

Stable sots or gels with SrBi 2 Nb 2 O 9 composition were obtained from mixtures of niobium ethoxide, bismuth and strontium 2-ethylhexanoates. SrBi 2 Nb 2 O 9 thin films were prepared by spin-coating a stable precursor solution on Si/SiO 2 /TiO 2 /Pt substrates. Randomly oriented 0.3 μm-thick crack-free films were obtained after 10 successive depositions and an heat-treatment of 2 hours at 700°C. Crystallisation occurs at about 550 °C and a pure SrBi 2 Nb 2 O 9 phase is obtained at 600°C. P-E hysteresis loops have confirmed the ferroelectric behaviour of the films: they show a remanent polarisation of 2.5 μC/cm 2 . No fatigue was observed up to 10 9 full switching.