RELATIONS BETWEEN MAGNETOOPTICAL PROPERTIES AND REACTIVITY IN COBALT-MANGANESE FERRITE THIN-FILMS AND POWDERS

Co-Mn spinel ferrites were prepared as submicron powders and thin film s. Because of their finely divided state, these spinels could be oxidi zed at low temperatures to give novel cation-deficient ferrites. For t hese two material forms, the magneto-optical properties were found to be strongly dependent on the ferrite oxidation state. The highest coer civities and Faraday rotations were obtained when the ferrites were pa rtially oxidized. These phenomena are attributed to the mechanical str ess effect developed during the oxidation of the manganese ions. The p roperties of these ferrites could be of interest for magneto-optical r ecording applications. The first static recording tests were performed at 780 nm wavelength.