High magnetization and the Faraday effect for ferrimagnetic zinc ferrite thin film

The magnetization and Faraday effect in the wavelength range of 350–850 nm have been measured for zinc ferrite thin film prepared by the sputtering method. X-ray diffraction analysis indicates that the thin film is single-phase ZnFe 2 O 4 , whose crystallite size evaluated from Scherrer’s equation is 10 nm or so. The thin film is extremely transparent for wavelengths longer than about 600 nm, and exhibits high magnetization, i.e., 32 emu g −1 , at 1 T even at room temperature. The absolute value of the Faraday rotation angle is 1.0 × 10 4 deg cm −1 at a wavelength of 470 nm when an external magnetic field of 5 kOe is applied.