Analysis of the effect of isotope scattering on the thermal conductivity of crystalline silicon

We present an analysis of recent thermal-conductivity measurements on crystalline silicon in which the concentration of the {sup 28}Si isotope has been increased above the natural abundance. We calculate from the phonon Boltzmann equation the change in the conductivity due to a change in isotope concentration. The conductivity change is evaluated numerically using a realistic model of the lattice dynamics of silicon. {copyright} {ital 1999} {ital The American Physical Society}