BIAXIALLY ORIENTED TL-1223 WIRE PREPARED ON CUBE-TEXTURED SILVER SUBSTRATE

To obtain Tl-1223 wires with a high critical current density (J(c)), T l-1223 layers are necessary to orient each other biaxially with the a- axis. The cube-textured silver tapes can be successfully prepared as t he substrate for realizing the well-oriented Tl-1223 layer. The cube t exture of silver tape was formed by heat treatment at temperatures hig her than 600 degrees C after rolling at an intermediate temperature. T he full width at half maximum of X-ray diffraction phi-scan of the tap e was typically 6 degrees. The homogeneously textured structure was ob tained over the 15 m long tape. The Tl-1223 thin layer was prepared on the cube-textured silver tape by spray pyrolysis method. The degree o f the a-axis orientation of Tl-1223 layer was improved by the substrat e effect. Due to this biaxial texturing, the grain boundary characteri stics were improved, that is, the J(c) was as high as 1.5 x 10(4) A/cm (2) at 77 K under an external field of 1 T. The present study demonstr ated that the Tl-1223 long scale wires with improved biaxial orientati ons can be manufactured by a combination of the simple heat treatment process for the cube-textured silver tape and the mass-productive spra y pyrolysis method for the biaxially oriented Tl-1223 thin layer.