Faraday Rotation of Co-Ferrite Thin Films Prepared by Single Source Evaporation

Fe-Co alloy film was oxidized to produce a transparent cobalt ferrite film. The amount of Faraday rotation was measured as a function of the quantity of Fe
²⁺
, which was increased and decreased by reduction and oxidation. In the film reduced to increase the amount of Fe
²⁺
, the Faraday rotation curve becomes positive. The absorption coefficient increases with increase in Fe
²⁺
. When the film is oxidized at 600°C, the Faraday rotation curve becomes negative again and the absorption coefficient decreases.