Title :
Field Dependence of Spin-Transfer Torque Switching Current in Perpendicular Magnetic Tunnel Junctions
Author :
Cuchet, Lea ; Sousa, Ricardo C. ; Vila, Laurent ; Auffret, Stephane ; Rodmacq, Bernard ; Dieny, Bernard
Author_Institution :
SPINTEC, CEA, Grenoble, France
Abstract :
Spin-transfer torque switching has been studied on (Co/Pt)/Ta/CoFeB/MgO/FeCoB/Ta patterned perpendicular magnetic tunnel junctions with nanopillar diameters ranging between 100 and 300 nm. Plotting current-field state diagrams, the critical current density for writing was found to be around 3 MA· cm-2. The field-current dependence of the state transition boundary is linear, with the slope depending on material parameters. Using different thicknesses of top FeCoB free layers, we were able to estimate the Gilbert damping parameter α .
Keywords :
boron alloys; cobalt; cobalt alloys; iron alloys; magnesium compounds; magnetic multilayers; magnetic switching; magnetic tunnelling; nanomagnetics; nanostructured materials; perpendicular magnetic anisotropy; platinum; tantalum; Co-Pt-Ta-CoFeB-MgO-FeCoB-Ta; Gilbert damping parameter; critical current density; current-field state diagrams; field-current dependence; nanopillar diameters; patterned perpendicular magnetic tunnel junctions; size 100 nm to 300 nm; spin-transfer torque switching current; state transition boundary; Anisotropic magnetoresistance; Critical current density (superconductivity); Current measurement; Junctions; Magnetic tunneling; Magnetomechanical effects; Switches; Magnetoresistive random access memories (MRAMs); perpendicular magnetic anisotropy (PMA); spin-transfer torque (STT) switching;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2014.2322390
