Magneto-optical properties of Ni-MgO and Co-MgO nanocomposite films obtained by partial reduction reactions

摘要

A new processing technique was developed to synthesize metal-ceramic films containing nano-sized Ni or Co particles embedded in a MgO matrix. Sol-gel solutions were upon on different substrates with varying coefficients of thermal expansion,oxidized by heating in air and reduced to form a metal-ceramic two phase mixture. This method allows the generation of perpendicular magnetic anisotropy by use of residual stresses arising from a coefficient of thermal expansion difference betwen the film and substrate. Magneto-optical measurements show that the films can have relatively large Kerr and Farday rotations, and that the metal particles have sufficient vertical magnetic anisotropy to support perpendicular magnetization. The kmagneto-optical properties of the films related to the metal particle size, film thickness and substrate choice.