Femtosecond Laser-Induced Magnetization Reversal Domain of Co-Sublattice in TbCo Film

All-optical switching (AOS) is an emerging recording technology by using femtosecond laser to manipulate the ultrafast magnetization reversal for future super high density magnetic storage. TbCo films possess a ferrimagnetic structure and large perpendicular anisotropy and, thus, become a potential material for AOS. In this paper, we simulate the ultrafast magnetization reversal domain of Co-sublattice in TbCo films under 100 fs pulse laser with a general theoretical framework, and our simulation results show that TbCo films irradiated with a higher power fluence laser have a larger reversal domain of Co-sublattice due to the higher peak temperature and the further critical isotherm of electrons. Moreover, high Co content can help Co-sublattice form a large reversal domain, but is unable to obtain the highly uniform reversal domain perhaps attributed to the insufficient anti-ferromagnetic interaction between Tb atoms and Co atoms.