Barium titanate thin films prepared on MgO (100) substrates by coating-pyrolysis process

Barium titanate (BaTiO₃) thin films were prepared on MgO (100) substrates using metal naphthenate solution by a coating-pyrolysis process. Amorphous films pyrolyzed at 470‡C were crystallized to BaTiO₃ phase by heat treatment at higher temperatures. The crystallinity and alignment of the films depended on temperature and on atmosphere during heat treatment. Epitaxial BaTiO₃ film having (100)-orientation was obtained by heat treatment at 900‡C under oxygen partial pressure of 2x 10^-4 atm. The epitaxial BaTiO₃ film had a lattice constant of 0.401₆ nm and displayed a smooth surface with some pores dispersed on the surface. By heat treatment in air, amorphous BaTiO₃ film was obtained at 900‡C or below, and textured film with less strong (100) orientation was obtained at 1,200‡C and consisted of grains with diameter about 0.3 Μ.