Improving the Signal-to-noise Ratio for Heat-Assisted Magnetic Recording by Optimizing a High/Low Tc bilayer structure

Abstract

We optimize the recording medium for heat-assisted magnetic recording by using a high/low $T_{\mathrm{c}}$ bilayer structure to reduce AC and DC noise. Compared to a former work, small Gilbert damping $\alpha =0.02$ is considered for the FePt like hard magnetic material. Atomistic simulations are performed for a cylindrical recording grain with diameter $d=5$nm and height $h=8$nm. Different soft magnetic material compositions are tested and the amount of hard and soft magnetic material is optimized. The results show that for a soft magnetic material with ${\alpha }_{\mathrm{SM}}=0.1$ and $J_{ij,\mathrm{SM}}=7.72\times 10^{-21}$J/link a composition with $50\%$ hard and $50\%$ soft magnetic material leads to the best results. Additionally, we analyse how much the areal density can be improved by using the optimized bilayer structure compared to the pure hard magnetic recording material. It turns out that the optimized bilayer design allows an areal density that is $1$Tb/in${}^2$ higher than that of the pure hard magnetic material while obtaining the same SNR.

arXiv comment7 pages, 7 figures

References in corpus (11)

• Atomistic spin model simulations of magnetic nanomaterials
• Temperature dependent magnetic properties of FePt: effective spin Hamiltonian model
• Thermally induced error: density limit for magnetic data storage
• Landau-Lifshitz-Bloch equation for exchange coupled grains
• Tunable magnetization damping in transition metal ternary alloys
• Breaking the thermally induced write error in heat assisted recording by using low and high Tc materials
• Fundamental limits in heat assisted magnetic recording and methods to overcome it with exchange spring structures
• Areal density optimizations for heat-assisted-magnetic recording of high density bit-patterned media
• Basic noise mechanisms of heat-assisted-magnetic recording
• Noise reduction in heat-assisted magnetic recording by optimizing a high/low Tc bilayer structure
• Systematic parameterization of heat-assisted magnetic recording switching probabilities and the consequences for the resulting SNR

Cited by in corpus (2)

• Models of Advance Recording Systems: A Multi-timescale Micromagnetic code for granular thin film magnetic recording systems
• Systematic parameterization of heat-assisted magnetic recording switching probabilities and the consequences for the resulting SNR