Thermopower of NiO/(Bi, Pb)-2223 composite

Abstract

Solid-state reaction method was used to prepare superconductor samples with nominal composition of (NiO)x(Bi1.6Pb0.4)Sr2Ca2Cu3O10−δ,where 0.0 ≤ x ≤ 0.2 wt%. The prepared samples were characterized by X-ray diffraction (XRD) as well as scanning electron microscopy (SEM). XRD patterns indicated that the addition of nano-NiO particles to (Bi, Pb)-2223 did not affect the tetragonal structure and their lattice parameters. The thermopower coefficient was measured as a function of temperature from 250 K down to 77 K, using a standard differential technique. The results were analyzed according to the two-band (Fermi-liquid) and the two-band with an extra linear term models. Pseudo gap temperature (T*), Fermi energy (EF) and Fermi temperature (TF) values were calculated and discussed in terms of nano-NiO additions.