Phase-resolved x-ray ferromagnetic resonance measurements of spin pumping in spin valve structures

TY - JOUR

T1 - Phase-resolved x-ray ferromagnetic resonance measurements of spin pumping in spin valve structures

AU - Marcham, M.K.

AU - Keatley, P.S.

AU - Yu, W.

AU - Hicken, R.J.

AU - Shelford, L.R.

AU - Cavill, S.A.

AU - Van Der Laan, G.

AU - Shafer, P.

AU - Arenholz, E.

AU - Neudert, A.

AU - Childress, J.R.

AU - Katine, J.A.

AU - Telling, N.D.

PY - 2013/5/21

Y1 - 2013/5/21

N2 - Element-specific phase-resolved x-ray ferromagnetic resonance (FMR) was used to study spin pumping within CoFe(3)/Cu(6)/ NiFe(5) (thicknesses in nanometers) spin valve structures with large areas, so that edge effects typical of nanopillars used in standard magnetotransport experiments could be neglected. The phase of precession of the CoFe fixed layer was recorded as FMR was induced in the NiFe free layer. The field dependence of the fixed layer phase contains a clear signature of spin transfer torque (STT) coupling due to spin pumping. Fitting the phase delay yields the spin-mixing conductance, the quantity that controls all spin transfer phenomena. The STT coupling is destroyed by insertion of Ta into the middle of the Cu layer.

AB - Element-specific phase-resolved x-ray ferromagnetic resonance (FMR) was used to study spin pumping within CoFe(3)/Cu(6)/ NiFe(5) (thicknesses in nanometers) spin valve structures with large areas, so that edge effects typical of nanopillars used in standard magnetotransport experiments could be neglected. The phase of precession of the CoFe fixed layer was recorded as FMR was induced in the NiFe free layer. The field dependence of the fixed layer phase contains a clear signature of spin transfer torque (STT) coupling due to spin pumping. Fitting the phase delay yields the spin-mixing conductance, the quantity that controls all spin transfer phenomena. The STT coupling is destroyed by insertion of Ta into the middle of the Cu layer.

UR - http://www.scopus.com/inward/record.url?scp=84878542696&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.87.180403

DO - 10.1103/PhysRevB.87.180403

M3 - Article

AN - SCOPUS:84878542696

SN - 1098-0121

VL - 87

JO - Physical Review B: Condensed Matter and Materials Physics

JF - Physical Review B: Condensed Matter and Materials Physics

IS - 18

M1 - 180403

ER -