BixY3-xFe5O12 thin films prepared by laser ablation for magneto-optical imaging of superconducting thin films

Bismuth substituted yttrium iron garnet (Bi-YIG) thin films (300 nm) are prepared on (1 1 1) gadolinium gallium garnet (GGG) substrates by laser ablation. The films have high specific Faraday rotation up to 26deg/micron and saturation field of 120 mT. They are used for magneto-optical (MO) imaging of superconductive YBa2Cu3O6+x (YBCO) thin films. It is found that although the observed intensities are lower than observed with thick films, the thinness of the films makes the background corrections possible at higher magnifications than is possible with standard LPE films. It was also found that zig-zag patterns disturbing MO-imaging using thick films are completely nonexistent.