Dresden 2011 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 80: Epitaxy and growth: Metals and semiconductors I

O 80.4: Vortrag

Donnerstag, 17. März 2011, 15:45–16:00, WIL C307

The Interaction of Copper with a Rhenium(1010) Surface — •Daniel Przyrembel and Klaus Christmann — Institut für Chemie und Biochemie, Freie Universität Berlin

Ultrathin Cu films have been deposited in UHV on a Re(1010) surface between 650 K and 800 K and studied by means of MEED, LEED and TPD. Two desorption states are observed between 1000 K and 1180 K. The low temperature α state exhibits zeroth order desorption kinetics, the high temperature β state shows first-order desorption for low Cu coverages shifting to zeroth order with increasing coverage. In-situ observation of the MEED (0,0) beam intensity during Cu deposition shows only one maximum that coincides with the saturation of the β TPD peak and a LEED (1× 1) structure. No other LEED structures were observed in the investigated coverage range in contrast to the behaviour of Au and Ag [1,2]. Linear superposition of the LEED I,V curves from the clean Re surface and the closed Cu layer reproduces the respective I,V curves for all Cu coverages in that range. Together with the data for Au and Ag on Re(1010) and for Au, Ag and Cu on Re(0001) [3] these findings suggest: (i) On Re(1010) Cu grows in a Stranski-Krastanov mode. (ii) The closed Cu layer is a bilayer with two atoms per unit mesh. (iii) The bilayer is formed from two-dimensional islands with local (1× 1) structure that show a temperature dependent phase transition towards a two-dimensional lattice gas.

[1] C. Pauls and K. Christmann, J. Phys.: Condens. Matter 21 (2009) 134012; [2] A. Vollmer, Ph.D. thesis, FU-Berlin (1999); [3] R. Wagner, D. Schlatterbeck, K. Christmann, Surf. Sci. 440 (1999) 231-251.