Current-Induced Magnetization Switching of CoFeB/Ta/[Co/Pd (Pt)]-Multilayers in Magnetic Tunnel Junctions With Perpendicular Anisotropy

We investigate magnetic properties of CoFeB/Ta/[Co/Pd (Pt)] multilayers and properties of magnetic tunnel junctions (MTJs) with the structures as a recording layer. CoFeB/Ta/[Co/Pd] multilayer shows a lower damping constant α than that of CoFeB/Ta/[Co/Pt] multilayer. We evaluate current-induced magnetization switching (CIMS) properties of the MTJs with CoFeB/Ta/[Co/Pd (Pt)] multilayers with the junction diameter of 15 (13) nm that show similar thermal stability factor. CIMS is observed for the MTJ with a CoFeB/Ta/[Co/Pd] multilayer at zero magnetic field, whereas it is observed for the MTJ with the CoFeB/Ta/[Co/Pt] multilayer only in the presence of an external field.