Berlin 2012 – scientific programme
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MA: Fachverband Magnetismus
MA 52: Poster II - Magnetic Heusler compounds, Magnetic shape memory alloys, Thin Films, Micro-/Nano-structured magnetic materials, Graphene, Spins in organics, Magnetic imaging, Surface Magnetism, Spin excitations/Torque, Spincaloric transport
MA 52.26: Poster
Friday, March 30, 2012, 11:00–14:00, Poster A
Tailoring perpendicular anisotropy in Co/Pd multilayers by ion irradiation — •Julia Osten1, Peter Greene2, Tamio Endo3, Nobuyuki Iwata4, Kilian Lenz1, Kai Liu2, and Jürgen Fassbender1 — 1Institute of Ion Beam Physics and Materials Research HZDR, Dresden, Germany — 2U.C. Davis Physics Department, Davis, CA, USA — 3Mie University, Tsu, Mie, Japan — 4Nihon University, Funabashi, Chiba, Japan
A major obstacle towards the increase in areal magnetic recording density and the decrease in bit size is the retention of thermal stability while maintaining reasonable write fields. Materials with graded magnetic anisotropy are promising candidates to solve this problem. Here we demonstrate the approach of using post-deposition Ar-ion irradiation to tailor the perpendicular anisotropy in Co/Pd multilayer thin films. The films, with uniform as well as graded perpendicular anisotropy, were synthesized by magnetron sputtering. Based on TRIDYN simulations, different primary ion energies (1-25 keV) are chosen to achieve varying penetration depths of the ions creating a depth dependent anisotropy grading. Before and after ion irradiation, MOKE as well as magnetometry measurements were employed to detect the changes of the magnetic properties. Upon ion irradiation, the Co/Pd films exhibit reduced coercivity and remanence with increasing fluence. Higher ion energies have a more pronounced effect on reducing the perpendicular anisotropy.
The work at UCD was supported by the US NSF (DMR-1008791 & ECCS-0925626).