Silicide thin films

Silicides of the rare earths, such as dysprosium, are known to form a variety of two-dimensional epitaxial layers on Si(111). Such film structures can be prepared using MBE by deposition of thin Dy films on clean Si surfaces and subsequent annealing at temperatures of 500 - 700 °C. Depending on the Dy coverage, submonolayer, monolayer and multilayer silicide structures are formed [1]. The monolayer and multilayer films consist of hexagonal DySi₂ and Dy₃Si₅, respectively, and are characterized by a two-dimensional metallicity [2].

© AG Dähne

Typical STM image of the 1x1 reconstructed hexagonal DySi₂ monolayer and the √3x√3 reconstructed Dy₃Si₅ multilayer. The right image shows an atomically resolved detail of the DySi₂ monolayer [1].

© AG Dähne

ARPES data (left) showing the electron energy dispersion (top) and the Fermi surface (bottom) of the DySi₂ monolayer and the respective schematic representations (right) [2].



[1] Atomic structure of thin dysprosium-silicide layers on Si(111), I. Engelhardt, C. Preinesberger, S.K. Becker, H. Eisele, and M. Dähne, Surface Science 600, 755 (2006).
[2] Energy surfaces of rare-earth silicide films on Si(111), M. Wanke, M. Franz, M. Vetterlein, G. Pruskil, B. Höpfner, C. Prohl, I. Engelhardt, P. Stojanov, E. Huwald, J. Riley, and M. Dähne, Surface Science 603, 2808 (2009).