Electrical and thermal properties of bulk superconductors Eu0.95Pr0.05Ba2(Cu1−xMx)3O7−δ (M=Fe, Ni, Zn and Mn)

High Temperature Superconductors REBa2Cu3O7 (RE=Y, Gd and Eu) For Possible Thermo-electric Applications

“…However, with co-doping we observe changes in lattice parameters. The XRD patterns of other rare-earth series are reported in our earlier communications [10,11]. Figure 2 shows the temperature dependence of figure of merit for pristine, Pr-doped as well as co-doped samples of Y0.95Pr0.05Ba2(Cu1-xMx)3O7-δ and it is seen that Z value for pristine sample of YBa2Cu3O7-δ (Y-123) remains almost constant for the temperature range 90<T<200 K. It may be mentioned that one can not estimate Z values below 90K because in this range of temperatures, σ tends to infinity and S tends to zero.…”

“…Thermo-power and thermal conductivity measurements were performed simultaneously using direct pulse method. The experimental details of electrical and thermal measurements are described in our previous communications [9][10][11].…”

“…We have modified the structure by doping at the rare earth as well as at Cu-site. The present communication is an outcome of our earlier thermal measurements done on pristine and transition metal co-doped compounds of RE0.95Pr0.05Ba2Cu3O7-δ with RE=Y, Gd and Eu [9][10][11]. The thermal conductivity and thermo-power measurements were carried out in the temperature range 10-300K in a closed cycle refrigerator using a direct pulse method.…”

“…They have shown that oxygen deficient samples show higher Z-values. However it is well-know that electrical conductivity, thermal conductivity and thermo-power strongly depend on nature of dopants and dopant concentration [8][9][10][11], thus, it would be interesting to explore other oxide superconductors where one can modify the stoichiometry and use suitable doping in order to achieve a fairly large value of Z.…”