Title :
Synthesis and properties of superconducting (Tl,Pb)-(Sr,Ba)-Ca-Cu-O thick films on Ag
Author :
Venturini, E.L. ; Voigt, J.A. ; Lamppa, D.L. ; Aselage, T.L. ; Roth, E.P.
Author_Institution :
Sandia Nat. Labs., Albuquerque, NM, USA
fDate :
6/1/1995 12:00:00 AM
Abstract :
We report successful texturing of screen-printed (Tl,Pb)-(Sr,Ba)-Ca-Cu-O thick (20 /spl mu/m) films on both LaAlO/sub 3/ and Ag foil using rapid thermal processing (RTP) followed by furnace annealing. An RTP cycle to /spl ap/915/spl deg/C for 20 seconds in Ar produces massive melting of the superconducting powder but not the Ag substrate. Subsequent annealing under O/sub 2/ in sealed Au foil with a Tl source yields a brick-wall microstructure consisting of c-axis aligned, plate-like grains. X-ray diffraction and Meissner data show a mixture of the Tl-1223 and Tl-1212 phases while energy-dispersive spectroscopy identifies the plate-like grains as the desired Tl-1223. Magnetization data suggest intergranular supercurrents flowing across the entire film. Critical current densities inferred from hysteresis are 9/spl times/10/sup 4/ A/cm/sup 2/ at 5 K in low fields, decreasing by a factor of 5 in 5 tesla.<>
Keywords :
Meissner effect; X-ray diffraction; annealing; barium compounds; calcium compounds; critical current density (superconductivity); crystal microstructure; high-temperature superconductors; lead compounds; magnetic hysteresis; magnetisation; powder technology; rapid thermal processing; spray coating techniques; strontium compounds; superconducting thin films; thallium compounds; thick films; 20 s; 5 K; 915 C; Ag; LaAlO/sub 3/; Meissner data; Tl-1212 phase; Tl-1223 phase; TlPbSrBaCaCuO; X-ray diffraction; brick-wall microstructure; critical current densities; energy-dispersive spectroscopy; furnace annealing; high temperature superconductors; hysteresis; intergranular supercurrents; low fields; magnetization; massive melting; plate-like grains; rapid thermal processing; screen-printed films; sealed Au foil; superconducting powder; superconducting thick films; texturing; thick films synthesis; Argon; Furnaces; Gold; Microstructure; Powders; Rapid thermal annealing; Rapid thermal processing; Substrates; Superconducting films; Thick films;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
