Berlin 2015 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 31: Liquid and Amorphous Metals IV: Structure and Electronic Properties of Glasses
MM 31.3: Vortrag
Mittwoch, 18. März 2015, 10:45–11:00, H 0107
Structure and electronic transport of amorphous Ga-Mn alloys — •Leopold Koch1, Hans Weber2, Martin Stiehler1, Steffen Schulze1, and Peter Häussler1 — 1Technische Universität Chemnitz, 09107 Chemnitz — 2Leibniz-Institut für Festkörper- und Werkstoffforschung, Helmholtzstraße 20, 01069 Dresden
The last years we reported on structure formation in binary amorphous Al-transition metal alloys (a-Al-TM). The formation of structure is the result of global resonance effects between the Fermi gas and the forming static structure. The resonance causes a pseudogap at EF and defines the observed transport properties. During structure formation the resonance gets optimized by hybridization effects between the TM-d- and Al-p-bands at EF. While this behavior proved to be nearly independent on the particular TMs, the necessity of Al as the second element was unclear. Accordingly, Al has been replaced by other elements from the boron group, e.g. Ga or In. In the present contribution we report on structural and electronic properties of a-Ga-Mn alloys.
Thin films (d≈50 nm) were deposited in high-vacuum at low T. The electrical resistivity was measured during annealing to several hundred K, the static atomic structure at around 300 K. Pure Ga itself becomes amorphous at very low T, but crystallizes already around T=14 K. By adding Mn the stability rises tremendously and amorphicity could be achieved in a wide concentration range. The overall structural as well as the electric transport properties of a-Ga-Mn are very close to a-Al-Mn. The magnetic behavior still has to be measured.