The authors report tunnel magnetoresistance (TMR) ratios as high as 472% at room temperature and 804% at 5 K in pseudo-spin-valve (PSV) CoFeBMgOCoFeB magnetic tunnel junctions (MTJs) annealed at 450 °C, which is approaching the theoretically predicted value. By contrast, the TMR ratios for exchange-biased (EB) SV MTJs with a MnIr antiferromagnetic layer are found to drop when they are annealed at 450 °C. Energy dispersive x-ray analysis shows that annealing at 450 °C induces interdiffusion of Mn and Ru atoms into the MgO barrier and ferromagnetic layers in EB-SV MTJs. Mechanisms behind the different annealing behaviors are discussed.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)