Magnetization reversal in half metallic Fe3O4 based pseudo spin valve nanomagnet arrays

Half metallic Fe₃O₄ with a fully spin-polarized band structure at the Fermi level is one of the most promising materials for magnetic random access memory (MRAM), which stores data in pseudo spin valve (PSV) or magnetic tunneling junction elements. Ordered arrays of such nanostructures provide the basic magnetic architecture required to produce MRAM. Fe₃O₄ (40 nm) / Cu (t_Cu) / Ni₈₀Fe₂₀ (30 nm) PSV structures were deposited on the patterned substrates using electron beam deposition technique. The M-H curves obtained for magnetic field applied along thetas = 0deg for an array of ellipse shaped Fe₃O₄(40 nm) / Cu (2 nm) / Ni₈₀Fe₂₀ (30 nm) PSV structure and a reference unpatterned film that was deposited under identical conditions. The reference film shows a sheared magnetization loop with high remanence, negligible coercive field and no distinct double switching characteristics. The anisotropy and interlayer coupling dominate the magnetic behaviour of the PSV elements.