Magneto-optical imaging of magnetic flux distribution in high-Tc superconductors

Prototype systems of home-made magneto-optical microscopes were fabricated, and preliminary studies were carried out using Bi2Sr2CaCu2O8+delta single crystals and an YBa2Cu3O7-delta superconductor vortex flow transistor. In the study using BSCCO crystals, we succeeded in the observation of magnetic flux penetration into half-peeled thin flake region on the crystal surface, and it was found that the magnetic fluxes penetrate in characteristic one-dimensional alignment almost along the crystal a-axis. On the other hand, in the study using the YBCO device clear changes in the generated magnetic field distribution could be detected corresponding to the current direction. (C) 2004 Elsevier B.V. All rights reserved.