Symmetry broken spin reorientation transition in epitaxial MgO/Fe/MgO layers with competing anisotropies

Isidoro Martínez (1) , Coriolan Tiusan (2) , Michel Hehn (3) , Mairbek Chshiev (4) , Farkhad Aliev (1)

1 UAM - Universidad Autónoma de Madrid
2 Technical University of Cluj-Napoca
3 IJL - Institut Jean Lamour
4 SPINTEC - SPINtronique et TEchnologie des Composants

The observation of perpendicular magnetic anisotropy (PMA) at MgO/Fe interfaces boosted the development of spintronic devices based on ultrathin ferromagnetic layers. Yet, magnetization reversal in the standard magnetic tunnel junctions (MTJs) with competing PMA and in-plane anisotropies remains unclear. Here we report on the field induced nonvolatile broken symmetry magnetization reorientation transition from the in-plane to the perpendicular (out of plane) state at temperatures below 50 K. The samples were 10 nm thick Fe in MgO/Fe(100)/MgO as stacking components of V/MgO/Fe/MgO/Fe/Co double barrier MTJs with an area of 20 × 20 μm2. Micromagnetic simulations with PMA and different second order anisotropies at the opposite Fe/MgO interfaces qualitatively reproduce the observed broken symmetry spin reorientation transition. Our findings open the possibilities to develop multistate epitaxial spintronics based on competing magnetic anisotropies.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Isidoro Martínez, Coriolan Tiusan, Michel Hehn, Mairbek Chshiev, Farkhad Aliev. Symmetry broken spin reorientation transition in epitaxial MgO/Fe/MgO layers with competing anisotropies. Scientific Reports, 2018, 8, pp.9463. ⟨10.1038/s41598-018-27720-7⟩. ⟨hal-01900888⟩