Effect of dislocations on the lattice thermal conductivity of superconducting niobium

Abstract

Thermal conductivity measurements on single crystal Nb samples in the superconducting state have demonstrated a resonant scattering of thermal phonons at roughly 5 × 10 10Hz. The assumption of a mechanical resonance associated with the dislocation structure accounts for the present data and is consistent with other data found in the literature. The thermalization of phonons at an abraded sample surface, and the attendant failure of the relation l −1 = ∑ j l j −1 for phonon mean free paths, was also observed.