X-ray studies of interface Fe-oxide in annealed MgO based magnetic tunneling junctions

► This work concludes the presence of oxide in MgO/transition-metal bi-layers. ► Thermal annealing causes a possible structural transformation of the oxide. ► This is first evidence for a possible structural change of the oxide. ► First use of the O K-edge XAS signature of TM oxides to confirm presence of oxide. ► We see a diffusion of oxygen and a decrease in interface roughness.