Magnetic Tunnel Junctions With Al2o3 Tunnel Barriers Prepared By Atomic Layer Deposition

Uniform Al2O3 tunnel barriers are fabricated with atomic layer deposition. The tunneling magnetoresistance in optimized Al2O3-based magnetic tunnel junctions is studied as a function of temperature in comparison with SrTiO3-based tunnel devices having the same La0.7Sr0.3MnO3 and Co electrodes. The junction resistance peaks at the onset temperature of the tunneling magnetoresistance which lies below the metal-insulator transition temperature of the La0.7Sr0.3MnO3 film. These results suggest a lower interface metal-insulator and ferromagnetic ordering temperature. (C) 2013 AIP Publishing LLC.