FeTaC Magnetic Soft Underlayer for L1_0 FePt Based Perpendicular Recording Media

摘要

FeTaC magnetic soft underlayer under elevated temperature process conditions for L1_0 FePt based perpendicular recording media has been investigated. After annealing FeTaC for 40 min at 350℃, saturation moment increases to 750 emu/cm~3 and, coercivity and remanent moment reduce to 2.3 Oe and 166 emu/cm~3 respectively. The microstructure of FeTaC annealed at 350℃ for 40 min composes of Fe nanocrystals with random orientations immersed in an amorphous matrix. FeTaC surface roughness due to elevated temperature process is reduced by 100 W RF plasma etching and CrRu with (200) orientation is developed. It is found that changing elemental composition due to C diffusion into the CrRu layer and RF preferential etching over Fe, Ta and C has the influence on the magnetic properties of FeTaC.