Diffusion in liquid and solid 3He- 4He mixtures
I.N. Adamenko, A.V. Zhukov, K.E. Nemchenko
Kharkov State University, 4 sq. Svobody, 310077, Kharkov, Ukraine
Office of the Chanбellor/Deаartment of Chemistry and Physics and Astronomy University of Wisconsin-Stevens Point, Stevens Point, Wisconsin, 54481-3897, U.S.A.
( Submitted November 15, 1996 )
Proceeding from the system of kinetic equations, the exact expression for diffusion time is obtained. This time turn out to be dependent on the interaction rates of particles both of different and the identical types. The results obtained are valid for particles with arbitrary statistics and the dispersion law. The derived general relations are used to investigate diffusion in liquid and solid 3He-4He mixtures. The contribution of the interaction between quasiparticles of the types to the coefficients of diffusion and thermal conductivity of superfluid mixtures are analyzed. The calculated values are compared with experimental data. The diffusion coefficient of solid 3He-4He mixtures is calculated and found to be different from results of previous theories. The comparison of the coefficient of spin diffusion with experimental data allows us to find the width of the energy zone of impurity quasiparticles.