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MM: Fachverband Metall- und Materialphysik

MM 65: Liquid & Amorphous Metals II

MM 65.7: Vortrag

Donnerstag, 14. März 2013, 18:45–19:00, H26

On structural and electronic properties of Al-Pd Alloys — •Pierre Pudwell, Nan Jiang, and Peter Häussler — Chemnitz University of Technology, Institute of Physics, 09107 Chemnitz

In recent years we reported on an electronic influence on phase stability of Al-3d-TM alloys (TM: Sc, …, Cu). The electronic influence is based on an internal exchange of momentum between global subsystems, namely the electronic system and the forming static structure. Both systems come into resonance to each other. The resonance is enhanced by hybridization effects between Al-p- and TM-d-states. Structure formation, phase stability and the evolution of electronic transport properties were found to be strongly related. In order to test whether such a hybridization enhanced resonance is also effective in other systems, we are about to extend our investigations to systems with 4d- and 5d-TM.

In our contribution we show data on Al-Pd alloys as representative for a system with 4d-TM. Thin films of the material were deposited in-situ at about 4K, the resistivity was measured during annealing from 4K to several hundred K, the static atomic structure after annealing to 350K. By comparing the diameter of the strongest diffraction ring with the diameter of the Fermi-sphere, stabilizing resonances were detected, indicating regions with different structural and electronic properties. Between 30 and 70 at.% Pd, there seems to be a hybridization effect like in the Al-3d-TM sytems. For higher and lower Pd concentrations a resonance effect without hybridization seems to dominate – comparable to simple amorphous alloys without transition metals.