Direct observation of vortex structure in a high-Tc YBa2Cu3O7-y thin film by Bitter decoration method

The Bitter decoration technique is one of the most powerful techniques to study the vortex structure of superconductor. The authors report the observation of vortex structure in a high Tc YBa2Cu3O7-y (YBCO) thin film by Bitter decoration method. The image of vortex structure was monitored by SEM, AFM and high resolution optical microscope. For magnetic field about 4--6mT, a vortex structure is seen. The vortex image varied with changing magnetic field. As compared with the vortex image of a Bi2Sr2CaCu2O8+y single crystal, the observed image appeared to be more randomly distributed