Role of crystal orientation on the magnetic properties of CoFe2O4 thin films grown on Si (1Â 0Â 0) and Al2O3 (0Â 0Â 0Â 1) substrates using pulsed laser deposition

We report the influence of crystal orientation on the magnetic properties of CoFe2O4 (CFO) thin films grown on single crystal Si (1 0 0) and c-cut sapphire (Al2O3) (0 0 0 1) substrates using pulsed laser deposition technique. The thickness was varied from 200 to 50 nm for CFO films grown on Si substrates, while it was fixed at 200 nm for CFO films grown on Al2O3 substrates. We observed that the 200 and 100 nm thick CFO-Si films grew in both (1 1 1) and (3 1 1) directions and displayed out-of-plane anisotropy, whereas the 50 nm thick CFO-Si film showed only an (1 1 1) orientation and an in-plane anisotropy. The 200 nm thick CFO film grown on an Al2O3 substrate was also found to show a complete (1 1 1) orientation and a strong in-plane anisotropy. These observations pointed to a definite relation between the crystalline orientation and the observed magnetic anisotropy in the CFO thin films.