engleski

Electrical and thermal transport properties of the complex metallic alloys o-Al13Co4, Al4(Cr, Fe) and icosahedral quasicrystals Al64Cu23Fe13

The investigations of the physical properties of the above compounds gave us some interesting results. In the complex metallic alloys o-Al13Co4 and Al4(Cr, Fe) we observed pronounced anisotropy of the electrical and magnetic properties. The temperature-dependent electrical resistivity of the samples Al4(Cr, Fe) and i- Al64Cu23Fe13 showed negative temperature coefficient along some crystallographic directions, which is different from the ordinary metallic compounds with a positive temperature coefficient. The reasons for this unusual behavior are in the first case slow charge carriers and in the second case a pseudogap in the spectral conductivity σ(ε) at the Fermi energy. The icosahedral quasicrystal i-Al64Cu23Fe13 shows a surprisingly low thermal conductivity for an alloy composed of regular metals, which is even lower than the thermal conductivity of some known thermal insulators like SiO2. Therefore, this quasicrystal shows an interesting combination of a moderately high electrical conductivity and a low thermal conductivity, not present in conventional metallic alloys.

complex metallic alloys ; electrical resistivity ; thermal transport ; quasicrystals

This work was done within the activities of the European Integrated Center for the Development of New Metallic Alloys and Compounds - C-MAC. The poster was presented by Stanislav Vrtnik.