Synthesis and Paraconductivity Studies of Fe-Pd Nanoparticles Added Cu sub(0.5) Tl sub(0.5) Ba sub(2) Ca sub(3) Cu sub(4) O sub(12- delta )Superconductors

Cu sub(0.5)Tl sub(0.5)Ba sub(2)Ca sub(3)Cu sub(4)O sub(12- delta )/(Fe-Pd 0, 0.5, 1.0, 1.5 %) superconductors are prepared at normal pressure by using three-step method. Alloy of Cu sub(0.5)Tl sub(0.5)Ba sub(2)Ca sub(3) Cu sub(4)O sub(12- delta )/(Fe-Pd 1 %) have shown maximum increase in the magnitude of superconductivity. Cu sub(0.5)Tl sub(0.5) Ba sub(2)Ca sub(3)Cu sub(4) O sub(12- delta )/(Fe-Pd 0, 0.5, 1.0, 1.5 %) samples have shown T sub(c)(R= 0) around 106, 105.3, 102, and 100 K and the onset of diamagnetism around 113, 110, 102, and 105 K, respectively. A comparison of X-ray diffraction (XRD) scans of Fe-Pd nanoparticles with Cu sub(0.5)Tl sub(0.5)Ba sub(2)Ca sub(3)Cu sub( 4) O sub(12- delta )/(Fe-Pd 0.5, 1.0, 1.5 %) superconducting samples have shown that the nanoparticles of Fe-Pd are quite stable in the matrix of Cu sub(0.5)Tl sub(0.5)Ba sub(2)Ca sub(3)Cu sub( 4) O sub(12- delta )samples even after repeated firing at 890 super([compfn])C. With increase addition of Fe-Pd nanoparticles, the axes length increases, showing some inclusion of nanoparticle into the unit cell of Cu sub(0.5)Tl sub(0.5)Ba sub(2)Ca sub(3)Cu sub( 4) O sub(12- delta )samples from the termination ends of crystal.The inclusion of Fe-Pd in the superconducting Cu sub(0.5)Tl sub(0.5)Ba sub(2)Ca sub(3)Cu sub( 4) O sub(12- delta )grains is also evidenced in Fourier transform infrared spectroscopy (FTIR) absorption measurements. The Fe-Pd nanoparticles added in Cu sub(0.5)Tl sub(0.5)Ba sub(2)Ca sub(3)Cu sub( 4) O sub(12- delta )samples have been found to decrease the population of inter-grain voids that is found to increase the coherence length along the c-axis and the inter-layer coupling J. The FIC analysis of conductivity data haveshown the Fe-Pd nanoparticles diffusing into the inter-grain sites promoted an increase of penetration depth lambda sub(p.d) and Ginzburg-Landau parameter, Kappa . Due to the this possible diffusion of the Fe-Pd nanoparticles in the superconducting grains, the T sub(c)(R= 0), B sub(c0)(T), B sub(c1)(T), and J sub(c)(0) values are suppressed in Cu sub(0.5)Tl sub(0.5)Ba sub(2)Ca sub(3)Cu sub( 4) O sub(12- delta )samples.