Relaxation Time of Lattice Waves in an Imperfect Crystal

概要

論文の詳細を見る
Relaxation time of lattice waves in a crystal containing many impurity atoms is obtained by using the double-time Green's function technique. Calculations are made for the case of substitutional impurity atoms in a simple cubic crystal. The Green's function is averaged over a random distribution of impurity atoms. From the averaged Green's function the relaxation time is obtained. When the strength of the perturbation due to impurities is small, the Rayleigh scattering occurs, and the reciprocal relaxation time is proportional to the parabolic expression c(1-c), where c is impurity concentration. For the strong perturbation there occurs the resonance scattering of lattice waves from the impurities. The resonance is dependent on impurity concentration. When the resonance occurs due to light impurity atoms, the effect of impurity concentration on the resonance is large. But for the resonance scattering from heavy impurities the effect of impurity concentration is small. In the limit of very small concentration, the result may be nearly equal to Yussouff's result.
社団法人日本物理学会の論文
1974-09-15