Deposition of epitaxial BiFeO3/CoFe2O4 nanocomposites on (001) SrTiO3 by combinatorial pulsed laser deposition

Abstract

BiFeO₃/CoFe₂O₄ (BFO/CFO) nanocomposites were grown on SrTiO₃ by pulsed laser deposition using a combinatorial method in which Bi_1.2FeO₃ and CoFe₂O₄ targets are alternately ablated. The films had the same vertically nanostructured morphology as thin films prepared by ablation of a single target, consisting of epitaxial CoFe₂O₄ pillars in a BiFeO₃ matrix. In a series of samples synthesized with a compositional spread, the out-of-plane magnetic anisotropy and the out-of-plane compressive strain of the CoFe₂O₄ pillars increased with decreasing volume fraction, and the anisotropy agreed with the value predicted from the strain state and magnetoelastic coefficients of CoFe₂O₄. These results show the dominant effect of magnetoelastic anisotropy in determining the magnetic hysteresis of the nanocomposite.