Room temperature magnetoresistance in CoFeB/SrTiO3/CoFeB magnetic tunnel junctions deposited by ion beam sputtering.

Room temperature transport properties are reported in polycrystalline SrTiO3-based magnetic tunnel junctions deposited by ion beam sputtering. The junctions comprise CoFeB electrodes and the SrTiO3 barrier with thickness varied between 0.9 and 1.9 nm. Resistance area product values between 3 Ω.μm2 and 22 kΩ.μm2 have been measured with a tunnel magnetoresistance ratio ranging from 3.1 to 13% at room temperature. At low barrier thickness (1.2 nm), ferromagnetic coupling between electrodes is observed, indicating the presence of defects in the structure. A post-oxidation step was found to improve transport properties at lower barrier thickness. [ABSTRACT FROM AUTHOR]