Thermal Conductivity And Thermo-Power Of Y1-X Pr-X Ba-2(Cu1-X M-X)(3)O7-Delta (M = Fe, Mn, Zn And Ni) Bulk Superconductors

In this paper, we present temperature dependent electrical conductivity rho(T), thermal conductivity kappa(T) and thermoelectric power S(T) for co-doped superconducting compounds Y0.95Pr0.5Ba2(Cu1-xMx)(3)O7-delta (M = Fe, Mn, Zn and Ni). The XRD patterns confirm that all the samples are single phased. Pristine YBa2Cu3O7-delta depicts a pronounced hump-like structure in kappa(T) below its transition temperature. With Pr-doping, a reduction in the peak height of the hump is observed. It is found that the hump structure is further suppressed with transition metal co-doping, and is viewed in terms of the phonon scattering with defect structure, electrons and phonons. S(T) data depicting a sign reversal with co-doping, has been analyzed in the framework of a narrow band model. (C) 2009 Elsevier Ltd. All rights reserved.