Epitaxial growth of spinel cobalt ferrite films on MgAl₂O ₄ substrates by direct liquid injection chemical vapor deposition

The direct liquid injection chemical vapor deposition (DLI-CVD) technique has been used for the growth of cobalt ferrite (CFO) films on (100)-oriented MgAl₂O₄ (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 Å and a saturation magnetization of 420 kA/m at room temperature. The Raman spectra of films on MgAl₂O₄ support the fact that the Fe³⁺- and the Co²⁺-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.