Ultrashort Laser Pulse Induced Magnetization Switching in In-plane Magnetized Ferrimagnetic CoGd

Jun-Xiao LIN^1*, Julius HOHLFELD¹, Michel HEHN¹, Thomas HAUET¹, Stéphane MANGIN¹

¹Physics, Institut Jean Lamour - Université de Lorraine, Nancy, France

* Presenter:Jun-Xiao LIN, email:jun-xiao.lin@univ-lorraine.fr

Storing information in magnetic media is an essential development in a nowadays technological product. Magnetization switching allows one to encode information through the change of pointing direction of spins either up or down by applying an external stimulus. For instance, the utilization of spin-polarized electrons, electric fields, and ultrafast laser pulses are being developed for magnetic manipulations. The last was initiated by exciting the ferromagnetic nickel film with the laser pulse, where the magnetization magnitude was rapidly quenched without experiencing the reversal. Indeed, magnetization switching can be achieved by applying the magnetic field when shooting the laser pulse; however, the requirement of the external field is not straightforward for energy-efficient magnetic storage devices.

A ferrimagnetic rare earth-transition metal (RE-TM) alloy contains two antiferromagnetic coupling magnetic sublattices. Its magnetic properties can be tuned by the relative magnetization magnitudes between two species. It has been demonstrated that single-pulse all-optical magnetization switching (AOMS) in (FeCo)_xGd_100-x with perpendicular magnetic anisotropy, but so far only for the limited range of concentration. Therefore, it is worth exploring how to extend the switching range. Here, we will introduce the AOMS in in-plane magnetized Co_xGd_100-x and the evolution with thickness and compare them with their perpendicularly CoGd counterpart.

Keywords: Ferrimagnetic CoGd, Magnetization switching, Ultrafast excitation