# Material and layer design to overcome writing challenges in bit-patterned media

R. Sbiaa, E. L. Tan, K. O. Aung, S. K. Wong, K. Srinivasan, S. N. Piramanayagam

Research output: Contribution to journalArticle

8 Citations (Scopus)

### Abstract

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.

Original language English 4782113 828-832 5 IEEE Transactions on Magnetics 45 2 https://doi.org/10.1109/TMAG.2008.2010644 Published - Feb 2009

### Fingerprint

Anisotropy
Magnetization
Magnetization reversal
Exchange coupling
Remanence
Composite structures
Multilayers
Composite materials
Experiments

### Keywords

• Bit-patterned media
• Perpendicular magnetic recording
• Switching field distribution

### ASJC Scopus subject areas

• Electrical and Electronic Engineering
• Electronic, Optical and Magnetic Materials

### Cite this

Sbiaa, R., Tan, E. L., Aung, K. O., Wong, S. K., Srinivasan, K., & Piramanayagam, S. N. (2009). Material and layer design to overcome writing challenges in bit-patterned media. IEEE Transactions on Magnetics, 45(2), 828-832. [4782113]. https://doi.org/10.1109/TMAG.2008.2010644

Material and layer design to overcome writing challenges in bit-patterned media. / Sbiaa, R.; Tan, E. L.; Aung, K. O.; Wong, S. K.; Srinivasan, K.; Piramanayagam, S. N.

In: IEEE Transactions on Magnetics, Vol. 45, No. 2, 4782113, 02.2009, p. 828-832.

Research output: Contribution to journalArticle

Sbiaa, R, Tan, EL, Aung, KO, Wong, SK, Srinivasan, K & Piramanayagam, SN 2009, 'Material and layer design to overcome writing challenges in bit-patterned media', IEEE Transactions on Magnetics, vol. 45, no. 2, 4782113, pp. 828-832. https://doi.org/10.1109/TMAG.2008.2010644
Sbiaa, R. ; Tan, E. L. ; Aung, K. O. ; Wong, S. K. ; Srinivasan, K. ; Piramanayagam, S. N. / Material and layer design to overcome writing challenges in bit-patterned media. In: IEEE Transactions on Magnetics. 2009 ; Vol. 45, No. 2. pp. 828-832.
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