Effect of point defects on the phonon thermal conductivity of bcc iron

Abstract

The effects of low concentrations of seven different substitutional impurities on the phonon thermal conductivity of iron were determined at 300 K. Of the seven solutes, Ni caused the smallest reduction and W the greatest. The data were analyzed on the basis of Callaway’s model, and the resulting impurity scattering was compared with theory. The data show that phonon scattering from the local strain field associated with point defects is smaller than predicted from theory, but not negligible. The results are consistent with theoretical formulas that show that mass difference and lattice-strain scattering can either reinforce or cancel.