Current-driven magnetization switching in low-resistance Co 40Fe40B20/MgO/Co40Fe 40B20 magnetic tunnel junctions (MTJs) is reported. The critical-current densities Jc required for current-driven switching in samples annealed at 270 and 300°C are found to be as low as 7.8 × 105 and 8.8 × 105 A/cm2 with accompanying tunnel magnetoresistance (TMR) ratios of 49 and 73%, respectively. Further annealing of the samples at 350°C increases TMR ratio to 160%, while accompanying Jc increases to 2.5 × 106 A/cm2. We attribute the low Jc to the high spin-polarization of tunnel current and small MsV product of the CoFeB single free layer, where Ms is the saturation magnetization and V the volume of the free layer.
|ジャーナル||Japanese Journal of Applied Physics, Part 2: Letters|
|出版ステータス||Published - 2005 9 30|
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