Structure and morphology of epitaxially grown Fe3O4/NiO bilayers on MgO(001)

THIN SOLID FILMS

卷:589

Article

Schemme, T.^1,2  Kuschel, O.^1,2  Bertram, F.³  Kuepper, K.^1,2  Wollschlaeger, J.^1,2 

[1] Univ Osnabruck, Fachbereich Phys, D-49069 Osnabruck, Germany

[2] Univ Osnabruck, Ctr Phys & Chem New Mat, D-49069 Osnabruck, Germany

[3] DESY Photon Sci, D-22607 Hamburg, Germany

关键词: Bilayer epitaxy;    Magnetite;    Nickel oxide;    Magnesium oxide;    Interface structure;    Thin film structure;    X-ray diffraction;   

DOI  :  10.1016/j.tsf.2015.06.018

来源: Elsevier

【 摘 要 】

Crystalline Fe3O4/NiO bilayers were grown on MgO(001) substrates using reactive molecular beam epitaxy to investigate their structural properties and their morphology. The film thickness either of the Fe3O4 film or of the NiO film has been varied to shed light on the relaxation of the bilayer system. The surface properties as studied by X-ray photoelectron spectroscopy and low energy electron diffraction show clear evidence of stoichiometric well-ordered film surfaces. Based on the kinematic approach X-ray diffraction experiments were completely analyzed. As a result the NiO films grow pseudomorphic in the investigated thickness range (up to 34 nm) while the Fe3O4 films relax continuously up to the thickness of 50 nm. Although all diffraction data show well developed Laue fringes pointing to oxide films of very homogeneous thickness, the Fe3O4/NiO interface roughens continuously up to 1 nm root-mean-square roughness with increasing NiO film thickness while the Fe3O4 surface is very smooth independent on the Fe3O4 film thickness. Finally, the Fe3O4/NiO interface spacing is similar to the interlayer spacing of the oxide films while the NiO/MgO interface is expanded. (C) 2015 Elsevier B.V. All rights reserved.

【 授权许可】

Free