CaFe2O4 thin films grown on (100)MgO substrates using pulsed laser deposition

Thin films (approximate to 0.4 mu m) of cobalt ferrite (CoFe2O4) have been grown on single-crystal (100) MgO substrates using pulsed laser deposition (PLD). The phase, orientation, and microstructure of the as-deposited films were investigated as a function of substrate temperature (i.e., 200-800 degrees C) at a constant oxygen deposition pressure of 30 mTorr. The as-deposited films were found to be single phase, well oriented, and approximately matching the stoichiometry of the target, but the cubic lattice constant of the films depended on the substrate temperature indicating that the films were strained. The greatest effect of-the substrate temperature was on the magnetic properties of the as-deposited films. At 800 degrees C, 4 pi M(s) was measured to be 5370 G which is approximately the accepted bulk value for cobalt ferrite. In addition, PLD cobalt ferrite films grown at substrate temperatures of 600 and 800 degrees C exhibited a uniaxial magnetic anisotropy with an easy direction normal to the film plane. Films grown at 200 and 400 degrees C also exhibited a uniaxial magnetic anisotropy but possessed a planar easy direction. (C) 1996 American Institute of Physics.