Al doping influence on crystal growth, structure and superconducting properties of Y(Ca)Ba2Cu3O7-y whiskers

作者：Calore L; Khan M M Rahman; Cagliero S^*; Agostino A; Truccato M; Operti L

来源：Journal of Alloys and Compounds, 2013, 551: 19-23.

DOI：10.1016/j.jallcom.2012.08.061

• Oxide superconductors
• Whiskers
• Superconductivity
• Powders-solid state reaction
• Growth mechanism

We synthesized Al doped Y(Ca)Ba2Cu3O7-y (YBCO) whiskers via the solid state reaction method. Al doping was systematically varied in the nominal cationic stoichiometry of YBa2Cu3CaTe0.5AlxO7-y, with 0 %26lt;= x %26lt;= 0.5. The amount of the grown whiskers increases for nominal Al addition up to x = 0.05, decreasing for larger concentrations. The concentration of Al incorporated in the crystals (x%26apos;) is always higher with respect to the starting stoichiometry and shows a gradient along its length, with a higher amount at the tip regions. The single crystal diffraction analyses show an increasing tetragonal character with increasing x%26apos;, with a transition from the orthorhombic to the tetragonal system for x%26apos; = 0.13, which is in agreement with the worsening of electrical transport properties and disappearing of superconductivity for x%26apos; = 0.19.

• 出版日期2013-2-25