Thermal Conductivity of LiF Containing Dislocations at Low Temperatures

Abstract

The thermal conductivity a t very low temperatures o f LiF crystals containing dislocations are analysed by using the Callaway model, Callaway's approximations, and approximations suggested by Kumar and Joshi. It is found that the contribution of the effective phonon-dislocation scattering processes to the lattice thermal conductivity can be calculated by suitably combining the static and the dynamic phonon-dislocation scattering processes.Die thermische Leitfahigkeit bei sehr tiefen Temperaturen von LiF-Kristallen mit Versetzungen wird mittels des Callaway-Modells, der Nitherungen von Callaway und der von Kumar und Joshi vorgeschlagenen Niiherungen analysiert. Es wird gefunden, daB der Beitrag der effektiven PhononVersetzung-Streuprozesse zur thermischen Gitterleitfahigkeit durch eine geeignete Kombination der statischen und dynamischen Phonon-Versetzung-Streuprozesse berechnet werden kann.

Lattice Thermal Conductivity of Deformed Lithium Fluoride Crystals at Low Temperatures

“…It is amazing that (3) leads to an excellent agreement. Kumar et al [13] have recently calculated the phonon conductivity by using Callaway's [14] and also Kazakov and Nagaev's [15] (also see Kumar and Joshi [IS]) expressions for the phonon conductivity with the following expression for the effective dislocation scattering processes :…”