title: Reduction of magnetic damping and isotropic coercivity and increase of saturation magnetization in Rh-incorporated CoIr system.
abstract: Replacing Ir with Rh in a CoIr system possessing negative uniaxial magnetocrystalline anisotropy (Ku) substantially reduces its magnetic damping and coercivity by more than half while retaining its high negative Ku. Moreover, a higher saturation magnetization (Ms) and more isotropic coercivity are achieved. Such material development makes it particularly suitable for use as the soft underlayer (SUL) of magnetic recording media for reducing noise, and as the oscillation layer of a spin-torque oscillator (STO) for achieving higher oscillation frequency, larger AC magnetic field and lower driving current, which can be readily integrated with the current recording head for microwave-assisted magnetic recording. Finally, we recommend a composite free layer by coupling CoIr with a spin polarizer (Co or Co/Cu/Co) for the enhancement of the spin-polarization rate and, therefore, the improvement of STO efficiency. These could pave the way for CoIr-based materials to be implemented in devices requiring a negative Kuwith low damping and high 'softness', such as oscillators.
authors.affiliation: Data Storage Institute, A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, #08-01 Innovis, Singapore 138634.
authors.forename: H S
authors.initials: HS
authors.lastname: Wong
authors.forename: S K
authors.initials: SK
authors.lastname: He
authors.forename: H J
authors.initials: HJ
authors.lastname: Chung
authors.forename: M S
authors.initials: MS
authors.lastname: Zhang
authors.forename: Kelvin
authors.initials: K
authors.lastname: Cher
authors.forename: Melvin
authors.initials: M
authors.lastname: Low
authors.forename: T J
authors.initials: TJ
authors.lastname: Zhou
authors.forename: Y
authors.initials: Y
authors.lastname: Yang
authors.forename: S K
authors.initials: SK
authors.lastname: Wong