Anisotropic Vortex Structure In Yba2cu3o7 Thin-Films At Liquid-Nitrogen Temperature

Bitter-pattern observations of the vortices for flux trapped at the liquid nitrogen temperature in YBa2Cu3O7 thin films with the c-axis and <110> direction parallel to the surface are reported. The penetration-depth anistropy is estimated to be 5 from the vortex shape. The shape and distribution of the spots give a visual description of the homogeneity in the film.