Regensburg 2007 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 10: Liquid and amorphous materials IV
MM 10.1: Vortrag
Montag, 26. März 2007, 16:15–16:30, H4
Structure and electronic transport of a-Nix(Ti50Al50)100−x — •Jan Rauchhaupt, Thomas Raubold, and Peter Häussler — Chemnitz University of Technology, Institute of Physics, 09107 Chemnitz, Germany
An approach to understand the development of any crystalline structure from the initial disordered state is to investigate stabilization processes in amorphous phases as precursors of any ordered structure. Amorphous thin films are ideal to do so because they exist in just one phase, can be prepared in exactly the right composition and the development of their structure and electronic transport properties dependent on the composition and temperature are easy to measure. In order to minimize their global energy many different alloys organize themselves under the influence of a resonant interaction between the valence electrons as one subsystem and the static structure as the other one. These resonances were observed in many systems, from simple metals and semiconductors to ionic glasses and TM-containing alloys (TM=transition metal). We discuss the results of the measurements as a hybridization effect of the Al-p-electrons with the empty d-states of the TM. Amorphous ternary alloys of Ni, Ti and Al were prepared in situ at T=4 K in a HV-cryostate and were annealed up to the crystalline state. The static structure, by means of electron diffraction, the resistivity and the thermopower were measured as a function of temperature and composition. Additionally quantitative White Lines measurements were performed to prove the predicted hybridization effects.