Magnetic and optical properties of MgAl2O4-(Ni0.5Zn0.5)Fe2O4 thin films prepared by pulsed laser deposition

摘要

Thin films composed of MgAl₂O₄ and ( Ni_0.5Zn_0.5)Fe₂O₄ ( [MA(100-x) -NZFx] films) were grown on fused SiO₂ substrates by pulsed laser deposition. X-ray diffraction measurements revealed that the films were polycrystalline, and that their lattice constant varied linearly with composition, indicating the formation of a solid solution. The film with x=60 was paramagnetic and those with x ≥ 70 were ferromagnetic. The films had a transparency above 75% in the visible range, but the transparency decreased with the x value. The optical band gaps were 2.95, 2.55, 2.30 and 1.89?eV for x=20 , 40, 60, 80 and 100, respectively. The Faraday rotation angle increased with x in the visible range, and the film with x=70 exhibited a value of 2000?degrees?cm^-1 at 570?nm, which is comparable to the rotation angle of Y₃Fe₅O₁₂ . Owing to their high transparency, which extends into the visible range, the [ MA(100-x) -NZFx] films can be used in novel magneto-optical devices.