Magnetic and magneto-optical properties of Co-MgF2 granular film prepared by co-evaporation for optical probe magnetic sensor

摘要

For the magneto-optical devices and sensors using the Faraday-effect, maintaining transmitted light intensity of a Faraday element is a key issue. A granular film with ferromagnetic fine metals dispersed in an insulator matrix has been expected to have both high transmittance and large Faraday-effect. The Co-MgF_2 granular film prepared by co-evaporation exhibited high transmittance when deposited in high substrate temperature. Also the saturation Faraday rotation angle per unit film thickness of 0.77 deg./μm at 1550 nm wavelength was obtained. Therefore, the Co-MgF_2 granular film will be useful for the optical probe magnetic sensor.