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 31.4: Vortrag
Mittwoch, 18. März 2015, 11:00–11:15, H 0107
Structure and electronic properties of amorphous In-Mn-alloys — •Benny Böhm, Syed Sajid Ali Gillani, Martin Stiehler, Steffen Schulze, and Peter Häussler — Technische Universität Chemnitz, D-09107 Chemnitz
Basic principles during structure formation have been reported in former contributions for binary amorphous Al-transition metal-alloys (a-Al-TM). Presently, Al in those alloys has been replaced by other elements of the boron group and the focus hence has shifted to a-Ga-Mn and a-In-Mn. Here we report on the latter. Structure and properties emerge from the coupling of two global subsystems, the Fermi gas and the structure-forming ions. Along several degrees of freedom and via an exchange of momentum they come into resonance and form a new equilibrium. Under resonance the electronic dispersion forms a pseudogap at EF with consequences on structure, its thermal stability, and electronic transport.
Thin films of In-Mn with different compositions from 40 - 70 at%Mn were deposited at low-T. The electrical resistivity up to several hundred Kelvin was measured and electron diffraction performed on a TEM at T=350 K. Close to this temperature a-In-Mn-alloys, unfortunately, seem to segregate into two phases, shows two main structural peaks in its structure factor S(K). One seems to be related to pure In, the other one to a phase which is still amorphous at T=350 K. Due to the two peaks in real space structural beats in the pair-distribution function g(r) occur. Transport properties support these indications.