Quasiparticle contribution to heat carriers relaxation time in DyBa

Quasiparticle contribution to heat carriers relaxation time in DyBa 2 Cu 3 O 7−x from heat diffusivity measurements. Abstract It is shown that the controversy on phonons or electrons being the most influenced heat carriers below the critical temperature of high-T c superconductors can be resolved. Electrical and thermal properties of the same DyBa 2 Cu 3 O 7−x monodomain have been measured for two highly different oxygenation levels. While the oxygenated sample DyBa 2 Cu 3 O 7 has very good superconducting properties (T c = 90 K), the DyBa 2 Cu 3 O 6.3 sample exhibits an insulator behavior. A careful comparison between measurements of the thermal diffu-sivity of both samples allows us to extract the electronic contribution. This contribution to the relaxation time of heat carriers is shown to be large below T c and more sensitive to the superconducting state than the phonon contribution .