Spin transfer switching characteristics in a [Pd/Co]_m/Cu/[Co/Pd]_n pseudo spin-valve nanopillar with perpendicular anisotropy

摘要

We successfully demonstrate spin transfer switching (STS) characteristics in a [Pd/Co]_m/Cu/[Co/Pd]_n pseudo spin-valve nanopillar with 100 nm diameter. We observed lower critical current density and high giant magnetoresistance (GMR) ratio in our devices compared to other fully perpendicularly magnetized pseudo spin-valve structures. The devices showed a current-perpendicular-to-plane GMR of 1.2% and a STS critical current density of J~(AP-P) = -2.6 × 10~7 A/cm~2 and J~(P-AP) = 3.8 × 10~7 A/cm~2. The observed low critical current density is thought to be due to higher spin-transfer efficiency arising from smaller spin orbital scattering, longer spin diffusion length of the thinner Pd, and thinner soft-layer-film thickness and coercivity in the nanopillar devices.