Preparation by in-situ reaction and physical characterization of Ag(Au) and Ag(Pd) sheathed (Tl, Pb, Bi) (Sr, Ba) 2Ca2Cu3O9−δ tapes

✍ Scribed by R.E. Gladyshevskii; A. Perin; B. Hensel; R. Flükiger; R. Abraham; K. Lebbou; M.Th. Cohen-Adad; J.-L. Jordan

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 634 KB
• Volume: 255
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(95)00612-5

✦ Synopsis

S upemonducting tapes with high-purity substituted TI(1223) powders (> 95 wt.%, Tc ~ 120 K) were produced by a new method based on an in-situ reaction under high pressure of helium (25 bar He/0.5 bar 02). A Ag(20 wt.% Au) alloy showed to be a good sheath material for an in-tape reaction up to 990°C, even when involving partial melting of the oxide which favors the grain growth. Due to an interaction between Pd and the oxide, a Ag(6 wt.% Pd) alloy is much less suitable for tape preparation. Reproducible transport critical current densities of 9 kA//cm 2 (77 K, 0 T) were obtained for Ag(Au) sheathed T1(1223) tapes with in-tape-reacted powder, the highest value being 10 kA/cm 2. The magnetic-field dependence of Jc of such tapes was improved with respect to Ag sheathed tapes with pre-reacted T1(1223) powders. Locally textured samples with up to 50 ixm large plate-like grains were obtained after partial melting in Ag(Au) sheathed tapes.