2006/02/28 by W. Chen, Wenyu Chen, A. D. Kent +4 · 2 citations
Materials Science · Physics and Astronomy · #Magnetic Properties and Applications #Magnetic properties of thin films #ZnO doping and properties #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.74.144408
published as Phys. Rev. B 74, 144408 (2006) · 5 Pages, 4 Figures
openalex publication_date 2006/10/06 · arxiv created 2007/09/13 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Spin transfer in asymmetric Co-Cu-Co bilayer magnetic nanopillars junctions has been studied at low temperature as a function of free-layer thickness. The phase diagram for current-induced magnetic excitations has been determined for magnetic fields up to 7.5\phantom\rule0.3em0exT applied perpendicular to the junction surface and free-layers thicknesses from 2\phantom\rule0.3em0exto\phantom\rule0.3em0ex5\phantom\rule0.3em0exnm. The junction magnetoresistance is independent of thickness. The critical current for magnetic excitations decreases linearly with decreasing free-layer thickness, but extrapolates to a finite critical current in the limit of zero thickness. The limiting current is in quantitative agreement with that expected due to a spin-pumping contribution to the magnetization damping. It may also be indicative of a decrease in the spin-transfer torque efficiency in ultrathin magnetic layers.