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MM: Metall- und Materialphysik

MM 21: Amorphous and Liquid Materials II

MM 21.5: Vortrag

Dienstag, 28. März 2006, 17:30–17:45, IFW D

Structure and transport properties of amorphous Ag-Sn Alloys — •D. Hauschild, S. Neubert, P. Haeussler, I. Kaban, and W. Hoyer — Chemnitz University of Technology, Institut of Physic, 09107 Chemnitz, Germany

Within the last years binary amorphous alloys of metal-metal and metal-semiconductor type were investigated resulting in a model of global resonances between the electronic system and the forming static structure [1].

Two of us (I K and W H) have measured the liquid state by means of X-ray diffraction. It was shown that the liquid state contains clusters of well defined composition and is micro-inhomogeneous. The variation of the overall composition results in a variation of their volume fraction, whereas the composition of the individual clusters stays constant. By decreasing the temperature the size of the clusters is increasing. Three of us (S N, D H and P H) have measured the amorphous state by means of electron diffraction in transmission. Here we compare a-Ag-Sn with l-Ag-Sn as well as with the corresponding states of Au-Sn and Cu-Sn. The results were discussed in the Hume-Rothery-Model with a possible enhancement by hypridization.

The amorphous alloys were prepared in situ at T = 4K in a HV-cryostate. Immediately after the evaporation and at various annealing steps, up to the crystalline state, we measured the static structure and the resistivity.

[1] P. Haeussler, Collective dynamics of nonlinear and disordered systems, Springer (2004)