A comparative study on the influence of the addition of different nano-oxide particles on the thermopower of (Bi,Pb)-2223 superconductor

Solid-state reaction technique was used to prepare superconductor samples with nominal composition of (SnO${}_2$)${}_x$(Bi,Pb)-2223 and (NiO)${}_x$(Bi,Pb)-2223, where 0.0 ≤ x ≤ 0.2 wt%. The prepared samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The impact of SnO${}_2$ and NiO nanoparticles addition on the thermopower of (Bi,Pb)-2223 was measured using a standard differential technique. The Seebeck coefficient values in the presence of NiO nanoparticles were about 5–37.9% higher than those obtained with the addition of SnO${}_2$ nanoparticles. Higher values of Seebeck coefficients result in a wide variety of applications of these superconductors such as electronics and thermoelectric devices. The obtained results were analyzed according to the two-band model (Fermi-liquid model) and the two-band model with an extra linear term. The Fermi velocity (υ${}_F$), Fermi energy, Fermi temperature (T${}_F$), Fermi wavenumber (K${}_F$), Fermi wavelength (λ${}_F$) as well as the carrier concentration (N/V) values were calculated and discussed as a function of the nanoparticles content.