Giant Faraday rotation in Fe–ZnSe granular films

The giant magneto-optical Faraday effect (giant Faraday rotation) of ferromagnetic metal–semiconductor matrix Fe–ZnSe granular films prepared by radio frequency sputtering is studied. The result shows that the Faraday rotation angle θF value of the granular films sample with Fe volume fraction x=35% is of the order of 105 °/cm at room temperature. Temperature dependence of the θF of Fe0.35(ZnSe)0.65 granular films shows that θF value, below 150 K, increases rapidly with the decrease of the temperature, and when T=10 K θF value is 6×105 °/cm. Through the study of the structure and dependence of magnetic properties on temperature, it has been found that the remarkable increase of the θF value of Fe0.35(ZnSe)0.65 granular films below 150 K seems to arise from the sp–d exchange interaction inside the granular films.