AMORPHOUS CHARACTERISTICS IN SPINEL FERRITES CONTAINING GLASSY OXIDES

Various kinds of flake-shaped amorphous ferrites have been produced by adding glassy oxides to spinel ferrites and furthermore by a rapidly quenching the molten ferrite. Various kinds of amorphous ferrite thin films have also been produced on a glass plate by means of a vacuum evaporation method. It was found that the magnetization of amorphous spinel ferrites is very low at room temperature, but becomes significantly larger at liquid helium temperature. Amorphous ferrite thin film possesses a large perpendicular anisotropy and a relatively large polar Kerr rotation angle. The results are discussed in connection with the Mossbauer spectra and the magnetic structure.