Electrical and thermal transport properties of Dy_0.95Pr _0.05Ba₂(Cu_1-x M_x)₃O _7-δ with (M=Fe, Co, Ni and Zn) bulk superconductors

In the present communication, measurements of transition temperature, thermal conductivity, thermoelectric power and specific heat have been carried out on pristine and co-doped samples of Dy_0.95Pr _0.05Ba₂(Cu_0.98 M_0.02) ₃O_7-δ system [M=Fe, Co, Ni and Zn]. The electrical resistivity results show that all the samples exhibit metallic behavior. The thermal conductivity results illustrate that for pristine sample of DyBa ₂Cu₃O_7-δ, the expected pronounced hump in thermal conductivity is seen below the transition temperature. The hump is suppressed with 5% Pr-doping and this is further suppressed with co-doping. The thermoelectric power measurements show that the pristine sample exhibits hole-like behavior and this continues for doped as well co-doped samples. Pristine sample shows the expected jump in specific heat and with Pr-doping a slope change is observed near the transition temperature.