Separation of quasiparticle and phononic heat currents in YBa2Cu3O7-delta

Measurements of the transverse (k(xy)) and longitudinal (k(xx)) thermal con ductivity in high magnetic fields are used to separate the quasiparticle th ermal conductivity (k(xx)(el)) of the CuO2-planes from the phononic thermal conductivity in YBa2Cu3O7-delta. k(xx)(el) is found to display a pronounce d maximum below T-c. Our data analysis reveals distinct transport (tau) and Hall (tau(H)) relaxation times below T-c: Whereas tau is strongly enhanced , tau(H) follows the same temperature dependence as above T-c.