Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Perpendicular Magnetic Anisotropy in FePt Patterned Media Employing a CrV Seed Layer | Kim et al. Nanoscale Res Lett 2011 6 13 http content 6 1 13 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Perpendicular Magnetic Anisotropy in FePt Patterned Media Employing a CrV Seed Layer 11 11 1 2 2 3 Hyunsu Kim Jin-Seo Noh Jong Wook Roh Dong Won Chun Sungman Kim Sang Hyun Jung Ho Kwan Kang3 Won Yong Jeong2 Wooyoung Lee1 Abstract A thin FePt film was deposited onto a CrV seed layer at 400 C and showed a high coercivity 3 400 Oe and high magnetization 900-1 000 emu cm3 characteristic of L10 phase. However the magnetic properties of patterned media fabricated from the film stack were degraded due to the Ar-ion bombardment. We employed a depositionlast process in which FePt film deposited at room temperature underwent lift-off and post-annealing processes to avoid the exposure of FePt to Ar plasma. A patterned medium with 100-nm nano-columns showed an out-of-plane coercivity fivefold larger than its in-plane counterpart and a remanent magnetization comparable to saturation magnetization in the out-of-plane direction indicating a high perpendicular anisotropy. These results demonstrate the high perpendicular anisotropy in FePt patterned media using a Cr-based compound seed layer for the first time and suggest that ultra-high-density magnetic recording media can be achieved using this optimized top-down approach. Introduction Conventional planar magnetic recording methods have been facing difficulties in reducing the thickness of a magnetic film and the average grain size in it which is required for the high bit density 1 2 . Furthermore these methods showed a bit density limit of about 100 Gbit in2 due to the magnetic moment instability termed superparamagnetism in very small grains and the magnetic exchange interaction between adjacent grains 1-4 . To overcome this limit a perpendicular magnetic recording was introduced where magnetic moments are aligned perpendicular to the film plane 5 6 . However a bit .
