Publications

The electrical resistivity of normal and superconducting states for SmBa2Cu3−x Ru x O7−δ (Sm-123) phase with 0.00 ≤ x ≤ 0.50, prepared by the conventional solid-state reaction technique, was studied. X-ray Powder Diffraction (XRD), Scanning Electron Microscope (SEM), Particle-induced X-Ray Emission (PIXE), Rutherford Backscattering Spectroscopy (RBS) and electrical resistivity measurements were performed in order to investigate the effect of Ru4+ ions substitution in Sm-123 phase. Both the phase formation and superconducting transition temperature T c enhance up to x=0.05. For x > 0.05, suppression of both the phase formation and T c is observed and the superconductivity is completely destroyed around x = 0.50. The normal-state electrical resistivity was analyzed by the two- and three-dimensional variable range hopping (2D-VRH and 3D-VRH) and Coulomb gap CG. The dominant mechanism for Sm-123 phase is CG with x ≤ 0.20 while is 3D-VRH for x ≥ 0.30.