The Effects of the Grain Sizes and the Heat Spot Geometry on the Transition Jitter in HAMR Technology

Thermal profile is one of the main factors that determine the shape of the magnetic footprint in heat-assisted magnetic recording (HAMR) technology. The characteristics of the magnetic footprint are one of the factors that influence the formation of the zig-zag or transition boundary in the two-dimensional (2-D) format. The transition boundary is calculated to obtain the transition jitter. The performance of HAMR technology can be identified by the transition jitter. In this work, transition boundary in 2-D format is used to identify the effect of the thermal profile. The thermal profile models are squircle, circle, and ellipse. Micromagnetic simulation based on the Landau-Lifshitz-Gilbert equation is used in the recording process. Moreover, grain size is investigated to determine the transition jitter. It was found that the squircle with grain size of 3 nm has the lowest average transition jitter.