R&D: Effect of Recording Conditions on Downtrack Thermal Gradient in HAMR

IEEE Transactions on Magnetics ( Volume: PP, Issue: 99 ) has published an article written by Stephanie Hernández, Zengyuan Liu, Steven Granz, Ian Gilbert, Drew Mader, Seagate Research, Seagate Technology, Shakopee, MN 55379 USA, Martin Blaber, Recording Head Operations, Seagate Technology, Bloomington, MN 55435 USA, Pin-Wei Huang, Recording Media Operations, Seagate Technology, Fremont, CA 94538 USA, Chris Rea, Recording Head Operations, Seagate Technology, Bloomington, MN 55435 USA, Ganping Ju, Recording Media Operations, Seagate Technology, Fremont, CA 94538 USA, and Tim Rausch, Seagate Research, Seagate Technology, Shakopee, MN 55379 USA.

Abstract: “Downtrack thermal gradient (DTG) is calculated for heat-assisted magnetic recording (HAMR) systems in both spin-stand experiment and micromagnetic model. DTG is an important parameter in HAMR. It describes the change in temperature in the vicinity of the write position. Recording conditions and media properties affect the switching process, which in turn affects the measured DTG. Trends in DTG versus different recording conditions such as linear velocity and applied field showed very good agreement between experiment and model. The model is also used to quantify the effect on DTG from parameters that are difficult to measure, such as Curie temperature distributions, anisotropy field distributions, and curvature. Finally, a breakdown of the contribution of the different conditions and properties considered on DTG is presented.“