Title :
Sprayed Tl-1223 films: formation kinetics and superconducting properties
Author :
Phok, Sovannary ; Galez, Philippe ; Jorda, J.-L. ; Peroz, C. ; Villard, C. ; De-Barros, Dominique ; Weiss, F.
Author_Institution :
Univ. de Savoie, Annecy, France
fDate :
6/1/2003 12:00:00 AM
Abstract :
TlBa2Ca2Cu3O9 superconducting films, 0.5 to 1 μm in thickness, have been prepared in a two step process. Using a nitrate solution, a precursor layer with composition Ba2Ca2Cu3Ox is first sprayed on a LaAlO3 heated substrate and then thallinated, following a procedure established for bulk samples. The critical temperature of the films ranges from 108 to 113 K, and the critical current density of the best samples reaches 0.7 MA/cm2. The reaction kinetics for the formation of the Tl-1223 phase between 880 °C and 910 °C has been studied for a better control of the grain growth and texture. The effect of fluorine addition on both the microstructure and superconducting properties have been also analyzed.
Keywords :
barium compounds; calcium compounds; critical current density (superconductivity); grain growth; high-temperature superconductors; spray coatings; superconducting thin films; superconducting transition temperature; texture; thallium compounds; 0.5 to 1 micron; 108 to 113 K; 880 to 910 degC; Tl-1223 phase; TlBa2Ca2Cu3O9; critical current density; critical temperature; fluorine addition effects; formation kinetics; grain growth; microstructure; sprayed Tl-1223 films; superconducting properties; texture; two step process; Annealing; Critical current density; High temperature superconductors; Kinetic theory; Magnetic films; Substrates; Superconducting epitaxial layers; Superconducting films; Temperature distribution; Thermal spraying;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2003.812025
