Bias-crafted magnetic tunnel junctions with bistable spin-dependent states

The authors have observed stable, reversible two-resistance states with substantial tunneling magnetoresistances of opposite signs in La0.7Sr0.3MnO3∕SrTiO3∕Co1−xCrx junctions. Electron energy loss spectroscopy studies reveal the segregation and oxidation of electrochemically reactive chromium at that interface, resulting in oxygen vacancies in the oxide barrier. Bias-induced switching between the two junction states is argued to reflect the incidence of these barrier defects at and near the electrically unstable SrTiO3∕Co1−xCrx interface. This affirms bias crafting as an additional lever in spintronic research across semiconducting spacers.