Textured growth of the high moment material Gd(0001)/Cr(001)/Fe(001)

F Stromberg (1) , C Antoniak (1) , U von Hörsten (1) , W Keune (1) , B Sanyal (2) , O Eriksson (2) , H Wende (1)

1 CeNIDE - Center for Nanointegration Duisburg-Essen
2 Department of Physics and Astronomy [Uppsala]

By magnetic coupling of Fe and Gd via Cr interlayers, the large local moment of Gd can be combined with the high Curie temperature of Fe. The epitaxial growth of a Gd film is studied here by preparing trilayer systems of Fe/Cr/Gd on MgO(100) substrates by molecular-beam epitaxy (MBE). The thickness of the Cr interlayer was varied between 3-5 monolayers. The structural quality of the samples was confirmed by in-situ RHEED and ex-situ XRD measurements. Epitaxial Cr(001)/Fe(001) growth was observed, as expected. By use of 57 Fe-CEMS (Conversion Electron Mössbauer Spectroscopy) in combination with the 57 Fe tracer layer method the Fe/Cr interface could be examined on an atomic scale and well separated Fe/Gd layers for all Cr thicknesses were confirmed. The unusual Gd/Cr crystallographic relationship of Gd(0001)Cr(001), with domains of the hexagonal Gd basal planes randomly oriented in the sample plane and not in registry with the underlying Cr(001) lattice, was found from combined RHEED and X-ray measurements. Annealing of the samples resulted in a remarkable improvement of the crystalline structure of the Gd layers. On the other hand, the appearance of a single line in the CEM spectrum leads to the conclusion that during annealing a small amount of Fe diffuses into the Cr layer. The electronic structure and magnetism of this system is investigated by first principles theory.

Mots clés: 81.15.Hi; 61.05.jh; 61.05.C; 76.80.+y; 76.50.+g; 75.70.Cn

F Stromberg, C Antoniak, U von Hörsten, W Keune, B Sanyal, et al.. Textured growth of the high moment material Gd(0001)/Cr(001)/Fe(001). Journal of Physics D: Applied Physics, 2011, 44 (26), pp.265004. ⟨10.1088/0022-3727/44/26/265004⟩. ⟨hal-00629467⟩