On the low-temperature thermal conductivity of Ni-doped Al2O3

Abstract

An attempt is made to explain the lower resonance anomaly in the thermal conductivity of Ni-doped Al2O3 by using τr ∼ ω-4s(ω2 - ω2r)2. An agreement between theory and experiment needs s = 0.71, and this is interpreted to mean that the frequency dependence of impurity-phonon coupling is approximately described by ω0.71 for phonons having frequencies in close neighbourhood of ωr. © 1975.