Magnetotransport properties and spin-torque effects in current perpendicular to the plane spin valves with Co–Fe–Al magnetic layers

The magnetotransport properties of current perpendicular to the plane giant magnetoresistive spin valves utilizing (CoxFe100−x)100−yAly alloys are investigated over a wide alloy composition range. (Co50Fe50)75Al25 is determined to be the approximate alloy composition that maximizes magnetoresistance. An increase in magnetoresistance from 1.7% for spin valves with standard Co50Fe50 to 3.3% for spin valves with (Co50Fe50)75Al25 is observed when substituting the same “magnetic” thickness in both the reference and the free layers. The spin-diffusion length for (Co50Fe50)75Al25 is determined to be less than approximately 35Å. Spin-torque measurements show that the spin-torque current density threshold is lower in CoFeAl spin valves compared to standard CoFe spin valves.