Structural and magnetic properties of pulsed laser deposited SrRuO/CoFeO/LaSrMnO magnetic oxide heterostructures on SrTiO(001) and MgO(001).

We report on the growth of all-oxide SrRuO/CoFeO/LaSrMnO and LaSrMnO/CoFeO/SrRuO heterostuctures on SrTiO(001) and MgO(001) substrates by pulsed laser deposition. Structural analyses by X-ray diffraction and transmission electron microscopy clearly indicate the preservation of epitaxial relations when the LaSrMnO layer is grown first, whereas trilayers with SrRuO at the bottom are more disordered. Both the substrate material and the deposition sequence strongly influence the formation of various structural defects such as interfacial dislocations and sub-grain structures, and this is clearly reflected by a reduction of the saturation magnetization in the top electrode. When the substrate material and the deposition sequence are correctly chosen, however, the magnetic moments of the LaSrMnO and SrRuO layers reverse independently, and the LaSrMnO layer retains bulk-like magnetic properties. [ABSTRACT FROM AUTHOR]