Enhancement of magnetic properties of Co/Pd multilayered perpendicular magnetic recording media by using Pd/Si dual seedlayer

Effects of the introduction of a Pd/Si dual seedlayer on the microcrystalline structure and magnetic properties of [Co/Pd]_n multilayered perpendicular magnetic recording media were investigated. The Pd/Si dual seedlayer was composed of a Pd upper seedlayer and a Si under seedlayer. The Pd upper seedlayer with a thickness of up to 10 nm markedly increased the coercivity of [Co/Pd]_n multilayered media in the direction perpendicular to the film surface. The highest coercivity of 7.8 kOe was obtained for the [Co/Pd]₁₀ medium with a Pd (10 nm)/Si (100 nm) dual seedlayer. The Pd upper seedlayer not only facilitated the formation of regular interfaces between the Co and Pd layers, but also reduced the thickness of the deteriorated initial layer in the [Co/Pd]_n multilayer, resulting in enhancement of the magnetic anisotropy field. The [Co/Pd]_n multilayered medium with the Pd/Si dual seedlayer exhibited weak intergranular exchange coupling between [Co/Pd]_n grains, which led to excellent read-write characteristics.