Effect of WO sub 3 doping on the properties of YBa sub 2 Cu sub 3 O sub 7 minus x superconductor

• Published in: Journal of applied physics 1990-01, Vol.67:1
• Main Authors: Padam, G.K., Tripathi, R.B., Singh, S., Rao, S.U.M., Jain, K., Kotnala, R.K., Goel, R.C., Khurana, B.S., Khullar, S.M., Das, B.K.
• Format: Article
• Language: English
• Subjects: 360204 - Ceramics, Cermets, & Refractories- Physical Properties; 656100 - Condensed Matter Physics- Superconductivity; ALKALINE EARTH METAL COMPOUNDS; BARIUM COMPOUNDS; BARIUM OXIDES; CHALCOGENIDES; COHERENT SCATTERING; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; COPPER COMPOUNDS; COPPER OXIDES; CRITICAL CURRENT; CRYSTAL STRUCTURE; CURRENTS; DIFFRACTION; DOPED MATERIALS; ELECTRIC CONDUCTIVITY; ELECTRIC CURRENTS; ELECTRICAL PROPERTIES; ELECTRON MICROSCOPY; MATERIALS; MATERIALS SCIENCE; MICROSCOPY; MICROSTRUCTURE; OXIDES; OXYGEN COMPOUNDS; PHYSICAL PROPERTIES; REFRACTORY METAL COMPOUNDS; SCANNING ELECTRON MICROSCOPY; SCATTERING; SUPERCONDUCTIVITY; THERMODYNAMIC PROPERTIES; TRANSITION ELEMENT COMPOUNDS; TRANSITION TEMPERATURE; TUNGSTEN COMPOUNDS; TUNGSTEN OXIDES; X-RAY DIFFRACTION; YTTRIUM COMPOUNDS; YTTRIUM OXIDES
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.345264

Tungsten-doped YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} superconducting samples are characterized with the help of resistivity, crystal structural, microstructural, density {ital d}, and critical current density {ital J}{sub {ital c}} studies for doping concentrations varying from 0.00 to 0.14 mol % of WO{sub 3}. It has been found that doping of WO{sub 3} has hardly any influence of {ital T}{sub {ital c}}, whereas it seems that {ital d} and {ital J}{sub {ital c}} are affected. {ital d} and {ital J}{sub {ital c}} of the samples increase in the range 0{lt}WO{sub 3}{le}0.04, but above this range, both start decreasing. The maximum {ital J}{sub {ital c}} obtained at 77 K and zero magnetic field in YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} doped with 0.04 mol % of WO{sub 3} is 450 A/cm{sup 2}. The lower concentrations ({lt}0.04 mol %) seem to improve the density, whereas higher concentrations lead to porous structure and also induce the formation of BaCuO{sub 2} and Y{sub 2}Ba{sub 1}Cu{sub 1}O{sub 5} nonsuperconducting phase as revealed by scanning electron microscopy, energy dispersive spectral, and x-ray diffraction analyses. The x-ray diffraction analysis also showed no appreciable change in the lattice parameters with WO{sub 3} doping. It appears that the WO{sub 3} doping changes the microstructure of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} to influence its {ital J}{sub {ital c}}.