Heat-Assisted Magnetization Dynamics in GdFeCo Using Field-Induced TR-MOKE

Abstract

A custom microcoil was used to generate a magnetic field pulse and a continuous wave (CW) laser was used as a heating source to study the heat-assisted effect in magnetization switching on GdFeCo thin films. Four different pulsed field strengths were chosen, and the power of the CW laser heating was varied from 0 to 180 mW. The heat-assisted enhancement was not observed when the pulsed field strength was 2400 Oe. The enhancement was visible when the pulsed field strength was reduced to 2160 Oe, and became obvious when the pulsed field strength was 1750 and 1350 Oe. These interesting results prove that CW laser heating could provide a marked improvement to the magnetization switching when the switching field is relatively small, thus making it a more applicable and economic alternative to pulsed laser heating. Simulations based on the Landau-Lifshitz-Bloch equation have also been performed and agreed well with the experimental data. The CW laser heating scheme provides a more economic and practical way to realize heat-assisted magnetization switching, which could be used for potential future heat-assisted magnetic recording technology.