Epitaxial growth of spinel cobalt ferrite films on MgAl_2O_4 substrates by direct liquid injection chemical vapor deposition

摘要

The direct liquid injection chemical vapor deposition (DLI-CVD) technique has been used for the growth of cobalt ferrite (CFO) films on (100)-oriented MgAl_2O_4 (MAO) substrates. Smooth and highly epitaxial cobalt ferrite thin films, with the epitaxial relationship MAO(100)[001]||CFO(100)[001], are obtained under optimized deposition conditions. The films exhibit bulk-like structural and magnetic properties with an out-of-plane lattice constant of 8.370 A and a saturation magnetization of 420 kA/m at room temperature. The Raman spectra of films on MgAl_2O_4 support the fact that the Fe~(3+)- and the Co~(2+)-ions are distributed in an ordered fashion on the B-site of the inverse spinel structure. The DLI-CVD technique has been extended for the growth of smooth and highly oriented cobalt ferrite thin films on a variety of other substrates, including MgO, and piezoelectric lead magnesium niobate-lead titanate and lead zinc niobate-lead titanate substrates.