Ion beam analysis and EPR studies for GdBa2Cu3−xRuxO7−δ superconducting phase

Superconducting samples of the type GdBa2Cu3−xRuxO7−δ with 0.000 ⩽ x ⩽ 0.300 were prepared by the conventional solid-state reaction technique. The phase formation percentage, lattice parameters, orthorhombic distortion and oxygen-content were calculated using X-ray powder diffraction (XRD) data. The real elemental-content of the prepared samples was estimated from particle induced X-ray emission (PIXE). In addition, the oxygen-content was determined using elastic Rutherford backscattering spectroscopy (RBS) technique at 3 MeV proton beam and Rietveld XRD analysis. Moreover, the prepared samples were investigated using electron paramagnetic resonance (EPR) measurements. The number of spins N participating in EPR resonance and the paramagnetic susceptibility χ were calculated as a function of both Ru-content and temperature. In addition, the activation energy Ea, Curie constant C, Curie temperature θ, the effective magnetic moment μ and the electronic specific heat coefficient γ were estimated as a function of Ru-content.

► Low Ru substitution in Gd-123 phase improved the physical properties of Gd-123 phase.
► PIXI technique is more accurate for determining the Ru-content than that EDX technique.
► The oxygen content increases as Ru-content increases.
► Number of spins and activation energy increased as Ru-content increases.
► The EPR line symmetric did not depend on both Ru-content and temperature.