Rev.Adv.Mater.Sci. (RAMS)
No 1, Vol. 18, 2008, pages 98-103

STRUCTURAL AND VIBRATIONAL PROPERTIES OF DEPOSITED Cu OR
Zr SURFACE ADLAYERS ON Cu46Zr54 BULK METALLIC GLASS

Dimitrios G. Papageorgiou, Andrius Ibenskas, Christina E. Lekka and Giorgos A. Evangelakis

Abstract

The structural and vibrational properties of Cu or Zr adlayers on Cu46Zr54 bulk metallic glass (BMG) were studied by means of Molecular Dynamics simulations based on a semi-empirical potential model in analogy to the Tight Binding scheme in the second moment approximation. We found that upon Zr deposition crystalline adlayers are formed, while mixed nearly crystalline terminal composition is found in the Cu deposition case. In addition, we found that at the very early stages of the depositions atomic rearrangement takes place at the interfaces very quickly, while the atomic diffusion within the adlayers is rather limited for temperatures up to 500K. Above this temperature some diffusive activity sets in the Zr adlayers, while the mixed adlayers are subject to reconstruction that is driven from Cu diffusion resulting in an amorphous face. Moreover, we found that the mean square displacements of the Zr adlayer increase linearly with temperature up to 600K, while for the Cu adlayer the same quantity at the higher temperature studied exhibits strong anharmonic increase.

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