Title :
The variation of Jcgb with GB misorientation and inclination measured using the scanning SQUID microscope
Author :
Tsai, Jack W.H. ; Chan, Siu-Wai ; Kirtley, John R. ; Tidrow, S.C. ; Jiang, Q.
fDate :
3/1/2001 12:00:00 AM
Abstract :
The scanning SQUID microscope was used to measure the Josephson penetration length (λJ) along the grain boundary. The Jc across the grain boundary was then derived from the λJ. YBa2Cu3O7-x (YBCO) films were deposited on a special set of SrTiO3 bicrystals to determine whether Jcgb varies as function of boundary inclinations (α´s). Our results showed that Jcgb decreased with α while α2 remained constant and vice-versa. The Jcgb decreased exponentially with misorientation (θ). In addition, SEM studies showed that the boundaries meandered on the length scan of 0.5-2 μm due to the island growth mode. The drop of Jcgb with increasing α1 and/or α2 is more than what can be explained by either the d-wave symmetry of its superconducting order parameters or boundary meandering
Keywords :
Josephson effect; barium compounds; critical current density (superconductivity); grain boundaries; high-temperature superconductors; penetration depth (superconductivity); scanning electron microscopy; superconducting thin films; yttrium compounds; Josephson penetration length; SEM; SrTiO3; SrTiO3 bicrystal substrate; YBa2Cu3O7-x; YBa2Cu3O7; boundary inclinations; boundary meandering; d-wave symmetry; films; grain boundary; grain boundary critical current density; island growth mode; scanning SQUID microscope; superconducting order parameters; Critical current density; Grain boundaries; High temperature superconductors; Length measurement; Lifting equipment; Materials science and technology; Q measurement; SQUIDs; Scanning electron microscopy; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
