Anisotropic electrical, magnetic and thermal transport properties of the Al₈₀Cr₁₅Fe₅ decagonal approximant

Abstract

The anisotropic magnetic, electrical and thermal transport properties were studied of a single-crystalline Al₈₀Cr₁₅Fe₅ approximant to the decagonal quasicrystal. The temperature-dependent electrical resistivity along the b and c crystalline directions shows non-metallic behaviour with a broad maximum, whereas it exhibits a metallic positive temperature coefficient along the a direction perpendicular to the (b, c) atomic planes. The resistivity can be treated with the model of slow charge carriers, where the increased electron–phonon scattering upon raising the temperature induces a transition from dominant Boltzmann (metallic) to dominant non-Boltzmann (insulating-like) regime. The magnetic susceptibility and thermal conductivity also reveal a small anisotropy.

Keywords:

• quasicrystals
• approximants
• electrical conductivity
• magnetic properties

Acknowledgements

This work was done within the activities of the 6th Framework EU Network of Excellence “Complex Metallic Alloys” (Contract No. NMP3-CT-2005-500140).