Figure 6

Dependence of W atom compositional depth profile on thickness of Fe diffusion barrier for double MgO-based p-MTJ spin-valves with top Co₂Fe₆B₂ free layer. (a) p-MTJ spin-valve without nanoscale-thickness Fe diffusion barrier, (b) p-MTJ spin-valve with 0.30-nm-thick Fe diffusion barrier. Free & spacer means the vertically stacked upper Co₂Fe₆B₂ free layer (1.0 nm)/W spacer (0.40 nm)/lower Co₂Fe₆B₂ free layer (1.0 nm)/Fe layer (0.44 nm).