Crystallinity and surface morphology of chemical solution derived epitaxial Bi4Ti3O12 thin films on (100)LaAlO3

Bi4Ti3O12 thin films were prepared on single-crystal (100)LaAlO3 substrates by chemical solution deposition using metal naphthenates as starting materials. Precursor films were pyrolyzed at 500°C for 10 min in air and finally annealed at 650, 700, 750 and 800°C for 30 min in air, followed by rapid cooling. Crystallinity and in-plane alignment of the thin films were investigated by X-ray diffraction θ–2θ scans and pole-figure analysis. A field emission-scanning electron microscope and an atomic force microscope were adopted for characterizing the surface morphology and the surface roughness of the films. Epitaxially grown thin films annealed at 650 and 700°C exhibited extremely flat surfaces. On the contrary, with the increase in annealing temperatures to 750 and 800°C, the columnar grain size and width of the films uniformly increased.