Original scientific paper

Thermal Conductivity of Taylor Phase Al₃(Mn,Pd) Complex Metallic Alloys

Denis Stanić ; Laboratory for the Physics of Transport Phenomena, Institute of Physics, Bijenička c. 46, P. O. Box 304, HR-10001 Zagreb, Croatia
Petar Popčević ; Laboratory for the Physics of Transport Phenomena, Institute of Physics, Bijenička c. 46, P. O. Box 304, HR-10001 Zagreb, Croatia
Igor Smiljanić ; Laboratory for the Physics of Transport Phenomena, Institute of Physics, Bijenička c. 46, P. O. Box 304, HR-10001 Zagreb, Croatia
Željko Bihar ; Laboratory for the Physics of Transport Phenomena, Institute of Physics, Bijenička c. 46, P. O. Box 304, HR-10001 Zagreb, Croatia
Ante Bilušić ; Laboratory for the Physics of Transport Phenomena, Institute of Physics, Bijenička c. 46, P. O. Box 304, HR-10001 Zagreb, Croatia; Physics Department, Faculty of Natural Sciences and Mathematics, University of Split, Nikole Tesle 12, HR-21000 Split, Croa
Ivo Batistić ; Department of Physics, Faculty of Science, University of Zagreb, Bijenička c. 32, HR-10000 Zagreb, Croatia
Jovica Ivkov ; Laboratory for the Physics of Transport Phenomena, Institute of Physics, Bijenička c. 46, P. O. Box 304, HR-10001 Zagreb, Croatia
Marc Hegen ; Institut für Festkörperforschung, Forschungszentrum Jülich, D-52425 Jülich, Germany
Michael Feuerbacher ; Institut für Festkörperforschung, Forschungszentrum Jülich, D-52425 Jülich, Germany

Abstract

Thermal conductivity, κ, of Taylor phase T-Al₇₃Mn_27–xPd_x (x = 0,2,4,6) complex metallic alloys (CMAs) has been studied in the temperature interval from 2 K to 300 K. The characteristics of κ are typical for the CMAs: a relatively small value, a change of slope at about 50 K and an increase of slope above 100 K. The value of κ is between 2.7 W/m K and 3.7 W/m K at room temperature. The low thermal conductivity has it’s origin in a complex structure: aperiodic on a short length scale, which leads to frequent electron scattering (i.e. to a low electronic contribution to the thermal conductivity), while the large lattice constant defines a small Brillouin zone that enhances umklapp scattering of extended phonons. Above 100 K the non-extended (localized) lattice vibrations are thermally excited, and hopping gives a new heat carrying channel resulting in typical increase of the thermal conductivity with temperature.

Keywords

thermal conductivity; Wiedemann-Franz law; Debye model; localized lattice vibrations; bipolar diffusion

Hrčak ID:

52241

URI

https://hrcak.srce.hr/52241

Publication date:

30.4.2010.

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