Fabrication of BaTiO₃ thin films and microdot patterns by halide-free nonaqueous solution route

This paper reports on the fabrication of barium titanate (BaTiO ₃) thin films using a precursor solution containing Ba and Ti alkoxides. l-proline was used to prevent the precipitation of Ba and Ti alkoxides in a mixed solvent of ethanol and butylcarbitol under ambient conditions. Analysis of X-ray diffraction and Raman spectra revealed that the as-deposited amorphous film crystallized into a tetragonal BaTiO₃ phase after annealing at 650°C in air. Scanning electron microscopic observations showed that the BaTiO₃ film was free from cracks even after annealing and exhibited good adhesion to the substrate. Because the precursor solution developed was sufficiently stable in air, dot patterning of BaTiO₃ was also performed using an inkjet system.