Superconducting and Magnetic Properties of Zn-doped YBa2Cu3O7−δ

• Published in: Journal of superconductivity and novel magnetism 2011-07, Vol.24 (5), p.1599-1605
• Main Authors: Liyanawaduge, N. P., Kumar Singh, Shiva, Kumar, Anuj, Awana, V. P. S., Kishan, H.
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Condensed Matter Physics; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Effects of crystal defects, doping and substitution; Exact sciences and technology; Magnetic Materials; Magnetic properties; Magnetism; Original Paper; Physics; Physics and Astronomy; Properties of type I and type II superconductors; Strongly Correlated Systems; Superconductivity; Transition temperature variations
• ISSN: 1557-1939; 1557-1947
• DOI: 10.1007/s10948-010-1063-7

The superconducting properties and AC/DC magnetic properties of YBa 2 Cu 3− x Zn x O 7− δ , ( x =0.0, 0.01, 0.03, 0.05, 0.10 and 0.15) compounds were investigated. Samples were synthesized through solid-state reaction route. X-ray diffraction data confirms the single-phase orthorhombic/tetragonal crystallization for the studied samples. Thermo-Gravimetric Analysis (TGA) was done for pure and Zn-doped YBa 2 Cu 3 O 7− δ (YBCO) samples. Results reveal that at higher dopant levels the doped samples are more oxygen-deficient than the undoped ones. The superconducting properties of YBa 2 Cu 3− x Zn x O 7− δ system always enhance with addition of oxygen to Cu–O chains, which causes enhancement of superconducting carrier density together with orthorhombic structure. Zn substitution causes an overall reduction of superconducting condensation energy with systematic degradation of superconducting properties like T c and J c . This occurs via induced non-homogeneity of hole carrier density created by extended nature of perturbation on electronic structure in CuO 2 planes and its weak-link type behavior. AC susceptibility measurement reveals that Zn doping reduces the inter-granular couplings. Scanning Electron Microscope (SEM) images indicate that increment of average grain size with increasing of Zn concentration.