Electronic transport properties of amorphous and quasicrystals TMxAl100−x alloys

Journal of Non-Crystalline Solids 353, 3237 (2007)
Liquid and Amorphous Metals XII – Proceedings of the 12th International Conference on Liquid and Amorphous Metals, 12th International Conference on Liquid and Amorphous Metals

J. Barzola-Quiquia and P. Häussler

Abstract

The electrical resistivity ρ(T), and the thermopower S(T), of amorphous films of (Mn,Fe)xAl100−x (15 less-than-or-equals, slant x less-than-or-equals, slant 50), as well Al70.5 Pd21Mn8.5and Al62.5Cu25Fe12.5 have been measured in the temperature range between 5 K and 350 K. The amorphous films were prepared in situby the sequential flash-evaporation technique at low temperature (T ≈ 10 K) and the quasicrystalline phases were obtained after annealing the samples to 900 K. The resistivity as well as the thermopower both show dependences on the TM-content and a pronounced non- metallic behaviour versus temperature. This behaviour can be explained in the frame of electronic stabilized amorphous systems, very similar to a Peierls effect in 1D-systems or Hume–Rothery alloys, where hybridisation effects of Al-p with TM-d electrons play an important rule. The electronic stabilization explanation is supported by resistivity and thermopower measurements, together with measurements of the static structure factor and the crystallisation behaviour of the amorphous samples. Finally, the resistivity and the thermopower both are fit to a model based on LMTO calculations, developed for TM-Al quasicrystalline materials, and supplies our description of the electronic density of states around the Fermi energy.