TY - JOUR
T1 - Material and layer design to overcome writing challenges in bit-patterned media
AU - Sbiaa, R.
AU - Tan, E. L.
AU - Aung, K. O.
AU - Wong, S. K.
AU - Srinivasan, K.
AU - Piramanayagam, S. N.
PY - 2009/2
Y1 - 2009/2
N2 - In this paper, the problem of writability in bit-patterned media (BPM) for high areal density will be discussed. A new film structure is proposed, made of a composite in-plane and perpendicular anisotropy layers to improve writability and reduce the time of magnetization switching in BPM. To demonstrate the efficiency of an in-plane anisotropy layer in assisting the switching of the magnetization of the high perpendicular anisotropy recording layer, we use micromagnetic simulation to study magnetization reversals in BPM for 5 Tb/in$^{2}$. Experiments have been carried out on patterned arrays of 60-nm-size dots made of [Co(0.3 nm)/Pd(0.8 nm)]$-{\times 15}$ multilayer and Co(2 nm)/[Co(0.3 nm)/Pd(0.8 nm)]$-{\times 15}$ composite structure. The mean switching field calculated from remanence magnetization curves shows a reduction of more than 50% from its initial value by adding a 2-nm-thick Co bottom layer with in-plane anisotropy. No difference in switching field distribution was observed in the two structures studied, indicating the merit of assisting the switching of high anisotropy patterned media by exchange coupling to an in-plane anisotropy layer.
AB - In this paper, the problem of writability in bit-patterned media (BPM) for high areal density will be discussed. A new film structure is proposed, made of a composite in-plane and perpendicular anisotropy layers to improve writability and reduce the time of magnetization switching in BPM. To demonstrate the efficiency of an in-plane anisotropy layer in assisting the switching of the magnetization of the high perpendicular anisotropy recording layer, we use micromagnetic simulation to study magnetization reversals in BPM for 5 Tb/in$^{2}$. Experiments have been carried out on patterned arrays of 60-nm-size dots made of [Co(0.3 nm)/Pd(0.8 nm)]$-{\times 15}$ multilayer and Co(2 nm)/[Co(0.3 nm)/Pd(0.8 nm)]$-{\times 15}$ composite structure. The mean switching field calculated from remanence magnetization curves shows a reduction of more than 50% from its initial value by adding a 2-nm-thick Co bottom layer with in-plane anisotropy. No difference in switching field distribution was observed in the two structures studied, indicating the merit of assisting the switching of high anisotropy patterned media by exchange coupling to an in-plane anisotropy layer.
KW - Bit-patterned media
KW - Perpendicular magnetic recording
KW - Switching field distribution
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U2 - 10.1109/TMAG.2008.2010644
DO - 10.1109/TMAG.2008.2010644
M3 - Article
AN - SCOPUS:60449114978
SN - 0018-9464
VL - 45
SP - 828
EP - 832
JO - IEEE Transactions on Magnetics
JF - IEEE Transactions on Magnetics
IS - 2
M1 - 4782113
ER -