engleski

The thermal conductivity of Al73Mn27-xFex Taylor phases

The thermal conductivity (κ ) of Al73Mn27-xFex (x=0, 2, 4, 6) complex metallic alloys has been measured in the temperature interval from 2 to 300 K. All the alloys are Taylor (T) phases, except Al73Mn21Fe6, which is decagonal (d) quasicrystal. The behaviours of κ are typical for complex metallic alloys, i.e., a relatively small magnitude, a change of slope at about 50 K and an increase of the conductivity above 100 K. At room temperature the magnitude of κ for all the samples is between 2.7 and 3.3 W/mK, which is comparable to that of thermally insulating amorphous SiO2 and Zr/YO2 ceramics. The reason for such a low thermal conductivity is because both, the electronic and lattice conductivity are low. The electronic contribution to the thermal conductivity is low because of the large electrical resistivity of the samples. The lattice thermal conductivity is greatly reduced because of the enhanced umklapp process of the phonon scattering (caused by the large lattice constant) and by the disorder in the structure.

complex metallic alloys ; thermal conductivity ; spectral conductivity

The paper (untitled "Thermal conductivity of T-Al73Mn27-xFex phases") was presented at the 16th International Scientific Meeting on Vacuum Science and Technique, Bohinj, Slovenija, (May 04-06, 2009)as a poster by Denis Stanić. This work was supported by the 6th Framework EU Network of Excellence 'Complex Metallic Alloys' (Contract No. NMP3-CT-2005-500140)