Title :
Investigation of magnetic flux trapping in high-Tc thin films by scanning SQUID microscope
Author :
Suzuki, Koji ; Adachi, Seiji ; Li, Yijie ; Utagawa, Tadashi ; Tanabe, Kazuki
Author_Institution :
Supercond. Res. Lab., ISTEC, Tokyo, Japan
fDate :
3/1/2001 12:00:00 AM
Abstract :
The behavior of flux trapping in NdBa2Cu3O y thin-film patterns with moats surrounding a 160 μm square area has been investigated by a scanning superconducting quantum interference device (SQUID) microscope. Magnetic images were taken for moat patterns with three types of configuration and different size after cooling below Tc in various fields, and the threshold field for complete flux expulsion from the moat-surrounded area was estimated. It was found that the threshold field strongly depends on the size and gap of moats as well as their configuration. The largest enhancement of the threshold field by a factor of approximately seven as compared with that for an isolated square pattern was observed for the continuous moat pattern with broken corners
Keywords :
SQUID magnetometers; barium compounds; flux pinning; high-temperature superconductors; neodymium compounds; scanning probe microscopy; superconducting thin films; 160 mum; NdBa2Cu3O; NdBa2Cu3Oy thin-film patterns; Tc; flux expulsion; high-Tc thin films; isolated square pattern; magnetic flux trapping; magnetic images; moats; scanning SQUID microscope; scanning superconducting quantum interference device (SQUID) microscope; threshold field; Digital circuits; Laboratories; Magnetic films; Magnetic flux; Magnetic force microscopy; SQUIDs; Sputtering; Superconducting magnets; Superconducting thin films; Superconductivity;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
