Spectral dependences of Faraday rotation in Y3-xBixFe5O12LPE films

Spectral dependences of the Faraday rotation in a series of the bismuth substituted yttrium iron garnet LPE films are studied in the visible and near infrared region. It is found that in the 0.5 to 3.0 eV photon energy range the spectral dependence ef Faraday rotation in YIG can well be approached by nine paramagnetic and one diamagnetic transition types, respectively. On Bi substitutions only two additional paramagnetic transitions and changes in two other transitions already present in YIG are sufficient to explain the spectral behavior of the whole system. A method of determining Bi contents in rather thin LPE films and at low Bi concentrations is suggested.