Ion Beam Analysis and Electric Properties of GdBa<SUB>2</SUB>Cu<SUB>3</SUB>O<SUB>7-δ</SUB> Added with Nanosized Ferrites ZnFe<SUB>2</SUB>O<SUB>4</SUB> and CoFe<SUB>2</SUB>O<SUB>4</SUB>

Abstract

In this study, superconducting samples of type GdBa2Cu3O7−δ added with x wt% (0 ≤ x ≤ 0.4) nanoferrites ZnFe2O4 and CoFe2O4 were prepared by the conventional solid-state reaction technique. The prepared samples were characterized using X-ray powder diffraction (XRD) in order to determine the volume fraction and lattice parameters. The elemental contents of the prepared samples were determined using particle induced X-ray emission (PIXE). In addition, the oxygen-content of these samples was obtained using non-Rutherford backscattering spectroscopy (RBS) at 3 MeV proton beam. It is found that the Oxygen-content of GdBa2Cu3O7−δ phase remains practically constant for low additions of both nanoferrites but it increases with high additions. The electrical resistivity of the prepared samples was measured by the conventional four-probe technique from room temperature down to the zero superconducting transition temperature (T0). An increase in the superconducting transition temperature Tc and the critical current density Jc is observed as x varies from 0.0 to 0.06 wt% of (ZnFe2O4)xGdBa2Cu3O7−δ, followed by a systematic decrease with increasing x. On the other hand, the Tc values for (CoFe2O4)xGdBa2Cu3O7−δ show a systematic decrease with x for both high and low additions while Jc is enhanced up to x = 0.01 wt% and decrease with further increase in x.

Investigation of the structural and electrical properties of CdO/(Bi, Pb)−2212 superconducting phase

“…All samples exhibit the normal metallic behavior for T>T c . The small curvature that appears above T c characterizes the fluctuations of the cooper pairs [54]. The fitting of the normal state resistivity data is done using Matthiessen's rule [55], as shown in figure 8 for the sample Cd-0, where ρ 0 represents the residual resistivity at 0 K and α is the resistivity temperature coefficient.…”