Comparative study of nano-sized particles CoFe sub(2)O sub(4) effects on superconducting properties of Y-123 and Y-358

• Published in: Physica. B, Condensed matter Condensed matter, 2014-10, Vol.450, p.7-15
• Main Authors: Slimani, Y, Hannachi, E, Salem, M K Ben, Hamrita, A, Varilci, A, Dachraoui, W, Salem, M Ben, Azzouz, F Ben
• Format: Article
• Language: English
• Subjects: Electrical resistivity; Nanostructure; Phases; Scanning electron microscopy; Superconductivity; X-ray diffraction; YBCO superconductors; Yttrium
• ISSN: 0921-4526
• DOI: 10.1016/j.physb.2014.06.003

The effects of nano-sized CoFe sub(2)O sub(4) particles (10 nm) addition on the structural and the normal state resistivity of YBa sub(2)Cu sub(3)O sub(7) (noted Y-123) and Y sub(3)Ba sub(5)Cu sub(8)O sub(18) (noted Y-358) polycrystalline were systematically studied. Samples were synthesized in oxygen atmosphere using a standard solid state reaction technique by adding CoFe sub(2)O sub(4) up to 2 wt%. Phases, microstructure and superconductivity have been systematically investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrical measurements [rho](T). XRD results reveal that the lattice parameters change for both Y-123 and Y-358 phases. SEM observations reveal that the grain size is reduced with increasing the content of CoFe sub(2)O sub(4). The measurements for the resistivity dependence of temperature show that the depression in superconducting temperature is more pronounced for CoFe sub(2)O sub(4) addition in Y-358 compound than in Y-123 one. These results may be attributed to the existence of much more disorder due to a greater number of Cu sites to be substituted by Fe and Co in Y-358 compared to Y-123.