Fig. 1. Sample structure and magnetic properties.
(A) MTJ stack structure with CoFeB/W/CoFeB as FL (red), CoFeB/W/Co/Ta/(Co/Pt)3 as RL (green), and (Co/Pt)6 multilayers as synthetic antiferromagnetic pinning layer (blue). Numbers in parentheses are the nominal thicknesses in nanometers. (B) Variation of the electron spin resonance field of the FL with the angle between the external magnetic field and normal direction of the sample consisting of only the FL section in (A). The black circles are experimental results; the solid red line fits with the Kittel formula. (C) m-H loop and magnetic moment directions of different functional layers for the MTJ multilayer stack with an out-of-plane (OOP) magnetic field. The inset is the minor loop between +2000 and −2000 Oe after presetting at +7000 Oe. emu, electromagnetic unit.