Thermal and field-rate dependence of multi-step magnetization switching of synthetic antiferromagnetic multilayers

Abstract

Synthetic antiferromagnetic (SAF) multilayers are a kind of functional materials with great potential for spintronic devices. Many excellent properties of SAF multilayers have been widely reported in previous works. Here, we experimentally found that the magnetization switching steps n of [Pt/Co]2/Ru/[Co/Pt]4 SAF multilayers with perpendicular magnetic anisotropy are highly dependent on the temperature and magnetic field sweeping rate by magneto-optic Kerr effect and anomalous Hall resistance measurement. It is found that the contribution of the upper and lower layers of the SAF multilayers to the anomalous Hall coefficients is different. The switching steps n change from 2 to 3 by reducing the thickness of the non-magnetic spacer, decreasing the sweeping rate of the magnetic field, and increasing the temperature of the measuring environment. Our findings could provide a method to achieve multi-step magnetization switching for functional spintronic devices.