Effect of substrates on epitaxy of Bi 4Ti 3O 12 thin films by dipping—pyrolysis process

Abstract

Bismuth titanate (Bi 4Ti 3O 12) thin films have been prepared on various substrates by the dipping—pyrolysis process using metal naphthenates as starting materials. The crystallinity and in-plane alignment of the films are analysed by X-ray diffraction θ-2 θ scans and β scans (polar diagrams), respectively. Highly c-axis-oriented Bi 4Ti 3O 12 thin films with smooth surfaces are obtained by heat treatment at 750°C on SrTiO 3 (100), LaAlO 3 (100) and MgO (100) substrates, while films grown on Si (100) exhibit polycrystalline characteristics. The fluctuation of in-plane alignment of epitaxially grown films depends on the lattice-misfit values between the films and the substrates used; Bi 4Ti 3O 12 films on MgO shows the largest full width at half maximum values in their β scans.