A NUMERICAL-ANALYSIS OF THE THERMAL-CONDUCTIVITY IN THE AB-PLANE OF YBA2CU3O7-DELTA

Measurements of the thermal conductivity in the ab-plane of different YBa2Cu3O7-delta single crystals in the temperature range 2 K < T < 120 K are presented. The crystals differ in oxygen content and density of defects like point defects and twin boundaries. A numerical analysis of the phonon thermal conductivity is described. It allows to separate the scattering rates for phonons due to the scattering-mechanisms bei ng effective in YBa2Cu3O7-delta. The phonon thermal conductivity is co nsidered only in the range of T < 1/3T(c) and T > T(c), because separa tion of the electron thermal conductivity from the measured total valu e is complicated between these two limits. The results of analyzing so me crystals provide a useful characterization of the mean densities of defects and show the dependence of the scattering mechanisms on the o xygen content.