Simulation of Heat Transfer in Multilayer Structure

Hard disk drives (HDDs) and recent data storage technologies are anticipated to play a transformative part in the development of information technology. Heat-assisted magnetic recording and its applications are one of the most significant technologies in this field, offering a pathway to noticeably higher storage densities. The thermal gradient in the tetralayer thin-film structure was generated by utilizing pulses of a femtosecond laser to produce a spin current. the tetralayer is made of an Al₂O₃- Py (Ni81Fe19)- MgO- Copper - YIG (Y₃Fe₅O₁₂)- and Gd₃Ga₅O₁₂ layers. To model the heat transfer and thermal gradients within this structure, COMSOL Multiphysics® software is used to conduct a detailed three-dimensional (3D) thermal simulation. Parameters such as thickness and time were shown to have a major effect on the generated spin current. In addition to that, the temperature gradients within the tetralayer are crucial indication for generating the spin current. The findings reveal that using MgO in the adjacent metallic layers did not provide sufficient thermal gradient, which is required to generate the spin current. Keywords: Thermal Gradient, Multilayer Thin Films, Spin current, Ultrafast laser, Heat-assisted magnetic recording, COMSOL Multi physics.