dc.contributor.author | Durrant, CJ | |
dc.contributor.author | Shelford, LR | |
dc.contributor.author | Valkass, RAJ | |
dc.contributor.author | Hicken, RJ | |
dc.contributor.author | Figueroa, AI | |
dc.contributor.author | Baker, AA | |
dc.contributor.author | van der Laan, G | |
dc.contributor.author | Duffy, LB | |
dc.contributor.author | Shafer, P | |
dc.contributor.author | Klewe, C | |
dc.contributor.author | Arenholz, E | |
dc.contributor.author | Cavill, SA | |
dc.contributor.author | Childress, JR | |
dc.contributor.author | Katine, JA | |
dc.date.accessioned | 2017-12-21T09:51:57Z | |
dc.date.issued | 2017-10-18 | |
dc.description.abstract | Spin pumping has been studied within Ta / Ag /
Ni
81
Fe
19
(0–5 nm) / Ag (6 nm) /
Co
2
MnGe
(5 nm) / Ag / Ta large-area spin-valve structures, and the transverse spin current absorption of
Ni
81
Fe
19
sink layers of different thicknesses has been explored. In some circumstances, the spin current absorption can be inferred from the modification of the
Co
2
MnGe
source layer damping in vector network analyzer ferromagnetic resonance (VNA-FMR) experiments. However, the spin current absorption is more accurately determined from element-specific phase-resolved x-ray ferromagnetic resonance (XFMR) measurements that directly probe the spin transfer torque (STT) acting on the sink layer at the source layer resonance. Comparison with a macrospin model allows the real part of the effective spin mixing conductance to be extracted. We find that spin current absorption in the outer Ta layers has a significant impact, while sink layers with thicknesses of less than 0.6 nm are found to be discontinuous and superparamagnetic at room temperature, and lead to a noticeable increase of the source layer damping. For the thickest 5-nm sink layer, increased spin current absorption is found to coincide with a reduction of the zero frequency FMR linewidth that we attribute to improved interface quality. This study shows that the transverse spin current absorption does not follow a universal dependence upon sink layer thickness but instead the structural quality of the sink layer plays a crucial role. | en_GB |
dc.description.sponsorship | The authors gratefully acknowledge the support of EPSRC Grant No. EP/J018767/1, and the award of the Exeter-Brown Scholarship in High Frequency Spintronics to C.J.D. | en_GB |
dc.identifier.citation | Vol. 96, article 144421 | en_GB |
dc.identifier.doi | 10.1103/PhysRevB.96.144421 | |
dc.identifier.uri | http://hdl.handle.net/10871/30741 | |
dc.language.iso | en | en_GB |
dc.publisher | American Physical Society | en_GB |
dc.rights | © 2017 American Physical Society | en_GB |
dc.subject | Ferromagnetism | en_GB |
dc.subject | Magnetotransport | en_GB |
dc.subject | Spin current | en_GB |
dc.subject | Spin polarization | en_GB |
dc.subject | Spin pumping | en_GB |
dc.subject | Spin relaxation | en_GB |
dc.subject | Spin transfer torque | en_GB |
dc.subject | Spin valves | en_GB |
dc.subject | Ferromagnetic resonance | en_GB |
dc.title | Dependence of spin pumping and spin transfer torque upon Ni81Fe19 thickness in Ta/Ag/Ni81Fe19/Ag/Co2MnGe/Ag/Ta spin-valve structures | en_GB |
dc.type | Article | en_GB |
dc.date.available | 2017-12-21T09:51:57Z | |
dc.identifier.issn | 2469-9950 | |
exeter.article-number | ARTN 144421 | en_GB |
dc.description | This is the final version of the article. Available from American Physical Society via the DOI in this record. | en_GB |
dc.identifier.journal | Physical Review B | en_GB |