Thermal conductivity of amorphous alloys above room temperature

Abstract

The thermal conductivity of ten amorphous alloys has been measured between 280 and 500 K. The thermal conductivity, K, can be separated into the electronic (Ke) and phonon (Kph) contributions. The electronic thermal conductivity, deduced from the Wiedemann–Franz law, varies almost linearly with temperature, whereas the phonon thermal conductivity shows a slower increase. At 300 K, Kph accounts for 34–49% of K. The phonon mean free path l is 12.5 Å for the binary alloy Fe80B20, but l decreases as the number of chemical components increases, reaching 7 Å for the five-component alloys Fe32Ni36Cr14P12B6 and Co66Fe4Mo2B12Si16. The metal-metal glasses, Cu70Zr30 and Cu45Zr55, have l values slightly larger than 11 Å, indicating that they have short-range order similar to that of Fe80B20.