Title :
Enhanced vertex pinning in annealed TlBa/sub 2/CaCu/sub 2/O/sub x/ thin films
Author :
Venturini, E.L. ; Newcomer, P.P. ; Siegal, M.P. ; Overmyer, D.L.
Author_Institution :
Sandia Nat. Labs., Albuquerque, NM, USA
fDate :
6/1/1997 12:00:00 AM
Abstract :
Furnace anneals of TlBa/sub 2/CaCu/sub 2/O/sub x/ thin films at temperatures above 500/spl deg/C cause partial TlO/sub x/ loss. High resolution transmission electron microscopy images reveal nanometer-scale discontinuities (pinched stacking faults) in the microstructure of annealed films. Significant increases in the vortex pinning potential and critical current density at elevated temperatures in strong magnetic fields are observed and are attributed to the presence of these localized defects.
Keywords :
barium compounds; calcium compounds; critical current density (superconductivity); defect states; flux pinning; high-temperature superconductors; localised states; superconducting thin films; thallium compounds; 500 C; TlBa/sub 2/CaCu/sub 2/O; annealed TlBa/sub 2/CaCu/sub 2/O/sub x/ thin films; critical current density; enhanced vertex pinning; furnace anneals; high resolution transmission electron microscopy; high temperature superconductor; localized defects; nanometer-scale discontinuities; partial TlO/sub x/ loss; pinched stacking faults; vortex pinning potential; Annealing; Critical current density; Furnaces; Image resolution; Magnetic films; Microstructure; Stacking; Temperature; Transistors; Transmission electron microscopy;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
