TbFeco film with W underlayer and overlayer for perpendicular magnetic recording

TbFeCo film is prepared with W underlayer and overlayer to protect the film from oxidation and its effect on the magnetic properties and domain structure of the film has been investigated. Only 5 nm overlayer and 20 nm underlayer can successfully protect the film from oxidation. The saturation magnetization increases with increase in underlayer thickness and the effect is more pronounced when TbFeCo films become thinner. W underlayer is very effective to prevent the reduction of remanent squareness ratio (S) with decrease in magnetic layer thickness. The value of S is 1.0 and 0.8, for the films with and without underlayer, respectively, where magnetic layer thickness was 15 nm. In magnetic force microscope observations, average magnetic domain size is reduced when W underlayer and overlayer are used.