Title :
Superconducting properties of Cu/sub 1-x/Tl/sub x/-1223 [Cu/sub 1-x/Tl/sub x/(Ba,Sr)/sub 2/Ca/sub 2/Cu/sub 3/O/sub 10-y/] thin films
Author :
Ihara, H. ; Sekita, Y. ; Tateai, H. ; Khan, N.A. ; Ishida, K. ; Harashima, E. ; Kojima, T. ; Yamamoto, H. ; Tanaka, K. ; Tanaka, Y. ; Terada, N. ; Obara, H.
Author_Institution :
Electrotech. Lab., Tsukuba, Japan
fDate :
6/1/1999 12:00:00 AM
Abstract :
The bi-axially-oriented thin films of Cu/sub 1-x/Tl/sub x/(Ba,Sr)/sub 2/Ca/sub 2/Cu/sub 3/O/sub 10-y/(Cu/sub 1-x/Tl/sub x/-1223: x=0.2-1.0) were prepared by an amorphous phase epitaxy (APE) technique on SrTiO/sub 3/ substrates. The amorphous phase was deposited by sputtering on the substrate and annealed in a thallium atmosphere at /spl sim/885/spl deg/C for /spl sim/50 min. Their T/sub c/ values were 100-113 K and higher than those of the YBa/sub 2/Cu/sub 3/O/sub 7-y/ (Y-123, that is, Cu-1212) system. Their J/sub c/ values were 2/spl times/10/sup 7/ A/cm/sup 2/ (77 K, 0 T) and 4/spl times/10/sup 5/ A/cm/sup 2/ (77 K, 10 T) at their maximum for x/spl sim/0.5. The J/sub c/ values were higher than the maximum values of Y-123 thin films by a factor of 2. The high J/sub c/ values are consistent with the low superconducting anisotropy (/spl gamma/=/spl xi//sub ab///spl xi//sub c/=2.5-4) of Cu/sub 1-x/Tl/sub x/-1223 and its high T/sub c/.
Keywords :
annealing; barium compounds; copper compounds; critical current density (superconductivity); high-temperature superconductors; sputtered coatings; strontium compounds; superconducting epitaxial layers; superconducting transition temperature; thallium compounds; (CuTl)(BaSr)/sub 2/Ca/sub 2/Cu/sub 3/O/sub 10/; 885 degC; Cu/sub 1-x/Tl/sub x/-1223; HTSC; SrTiO/sub 3/; SrTiO/sub 3/ substrates; [Cu/sub 1-x/Tl/sub x/(Ba,Sr)/sub 2/Ca/sub 2/Cu/sub 3/O/sub 10-y/] thin films; amorphous phase epitaxy; annealing; bi-axially-oriented thin films; critical current density; low superconducting anisotropy; sputtering; superconducting properties; transition temperature; Amorphous materials; Chemicals; Grain boundaries; Sputtering; Substrates; Superconducting epitaxial layers; Superconducting thin films; Temperature dependence; Transistors; X-ray scattering;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
