Effect of molybdenum and vanadium on the lattice thermal conductivity and Lorenz number of chromium

Abstract

The thermal conductivity and electrical resistivity of three Cr alloys with 3.89- and 9.35-at.% Mo and 4.57-at.% V have been measured in the temperature range from 3 to 300 K. The lattice thermal conductivity derived from these measurements is found to have maximum between 40 and 60 K and a magnitude at these temperatures that is much less than theoretical estimates. Point defects cannot explain these low magnitudes. Since the magnitude of the lattice thermal conductivity tends to increase as the Néel temperature of the alloy series decreases, there may possibly be phonon-magnon scattering present. All alloys show anomalously large values of the Lorenz number at temperatures above 100 K of the sort that has been seen in pure Cr. The lattice thermal conductivity is too small to explain this anomaly, and it must be an electronic effect as has been proposed.