Thermal Effect in a 3-D Simulation within Multilayer Thin Film of Ultrafast-Pulsed Laser

Abstract

Hard disk drive (HDD) and storage media have the potential to revolutionize future information technology. Heat-assisted magnetic recording (HAMR) is a promising method for increasing hard disk storage density and it is one of the applications of this study. The essential component of nanoscale spintronic devices is spin current. The simulation of a thermal gradient to generate a pure spin current using an ultrafast femtosecond (fs) laser in a multilayer thin film is presented. The trilayer sample (ferromagnetic/spacer/magnetic insulator) is the candidate to achieve the spin current. Ultrafast laser with fs pulse width simulated to creates a spin diffusion spark. These pulses penetrate within the trilayer reaching the magnetic insulator due to the penetration depth that record the effect. COMSOL Multiphysics software® is used to simulate the thermal behavior within the trilayer with three-dimensional (3-D) view. The thickness of the ferromagnetic layer (Ni81Fe19) has been shown to generate a high-temperature gradient within the magnetic insulator and therefore a larger spin current.