Effect of acetoin as chelating agent in the preparation of SrBi2Ta2O9 thin films from non-hydrolysing precursors

R. MACHADO; M.L. SANTIAGO; M.G. STACHIOTTI; A. FRATTINI; N. PELLEGRI; R. BOLMARO; O. DE SANCTIS

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY

Año: 2008 vol. 48 p. 294 - 302

0928-0707

Ferroelectric thin films of strontium bismuth tantalate (SBT) have been fabricated by a chemical solution deposition technique using non-hydrolyzing precursors. Strontium acetate, bismuth nitrate and tantalum ethoxide were used as precursor materials, with methanol and glacial acetic as solvents. We investigate the effects of the precursor chemistry, by the selection of the chelating agent, on the elimination of residual organic compounds, thermal evolution of phase formation, and microstructure evolution of derived films. We found that the utilization of alkanolamines as chelating agent produce the segregation of metallic bismuth in as-prepared powders. On the other hand, acetoin, one of the hydroxyketones, showed the elimination of residual organics at low temperature, an earlier onset of crystallization, and no segregation of secondary phases during the whole crystallization process. A comparative investigation of the surface microstructure, grain size distribution, crystallinity, and degree of crystal orientation of films fabricated with the different chelating agents is presented. The dielectric and ferroelectric properties of films prepared with acetoin are investigated.