Bi xY 3− xFe 5O 12 thin films prepared by laser ablation for magneto-optical imaging of superconducting thin films

Abstract

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 26°/μm and saturation field of 120 mT . They are used for magneto-optical (MO) imaging of superconductive YBa 2Cu 3O 6+ 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.