Title :
Effects of oxygen partial pressure and mechanical deformation on (Tl,Pb)(Ba,Sr)/sub 2/Ca/sub 2/Cu/sub 3/O/sub y/ Ag-sheathed tapes
Author :
Salazar, K.V. ; Peterson, E.J. ; Holesinger, T.G. ; Bingham, B. ; Coulter, J.Y. ; Sebring, R.J. ; Voigt, J.A. ; Roth, E.P. ; Haldar, P.
Author_Institution :
Los Alamos Nat. Lab., NM, USA
fDate :
6/1/1995 12:00:00 AM
Abstract :
The powder in tube method was used to produce silver sheathed tapes of Tl/sub 0.78/Pb/sub 0.5/Ba/sub 0.4/Sr/sub 1.6/Ca/sub 2/Cu/sub 3/O/sub y/. A precursor powder of Pb/sub 0.5/Ba/sub 0.4/Sr/sub 1.6/Ca/sub 2/Ca/sub 3/O/sub y/ (prepared via the hydroxycarbonate coprecipitation of the metal ions from a stoichiometric nitrate solution) was thallinated and packed into a silver tube and processed into tape. The tape was then heated (in 100% oxygen or air) from 840/spl deg/C by 870/spl deg/C for various anneal times. The effects of different intermediate pressing stresses during tape processing had dramatic effects on both the current-carrying capacity and the tape microstructure. Variation of pO/sub 2/ also led to differences in current-carrying capacity I/sub c/ as did a roll substituted for a press during tape processing.<>
Keywords :
barium compounds; calcium compounds; critical current density (superconductivity); crystal microstructure; deformation; high-temperature superconductors; lead compounds; materials preparation; silver; strontium compounds; superconducting tapes; thallium compounds; (Tl,Pb)(Ba,Sr)/sub 2/Ca/sub 2/Cu/sub 3/O/sub y//Ag-sheathed tapes; 840 to 870 C; Ag; Pb/sub 0.5/Ba/sub 0.4/Sr/sub 1.6/Ca/sub 2/Ca/sub 3/O/sub y/; Tl/sub 0.78/Pb/sub 0.5/Ba/sub 0.4/Sr/sub 1.6/Ca/sub 2/Cu/sub 3/O; current-carrying capacity; high temperature superconductor; hydroxycarbonate coprecipitation; intermediate pressing stresses; mechanical deformation; oxygen partial pressure; powder in tube method; precursor powder; stoichiometric nitrate solution; tape microstructure; tape processing; thallinated; Annealing; Critical current; Impurities; Laboratories; Microstructure; Oxygen; Powders; Pressing; Stress; Superconductivity;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
