The role of the non-magnetic material in spin pumping and magnetization dynamics in NiFe and CoFeB multilayer systems

Journal Article · Tue Apr 28 00:00:00 EDT 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4918909· OSTI ID:22402910

Brächer, T.; Lauer, V.; Pirro, P.; Heinz, B.; Geilen, M.; Chumak, A. V.; Conca, A.; Leven, B.; Hillebrands, B. ^[1]

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1. Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern (Germany)

We present a study of the effective magnetization M{sub eff} and the effective damping parameter α{sub eff} by means of ferromagnetic resonance spectroscopy on the ferromagnetic (FM) materials Ni{sub 81}Fe{sub 19} (NiFe) and Co{sub 40}Fe{sub 40}B{sub 20} (CoFeB) in FM/Pt, FM/NM, and FM/NM/Pt systems with the non-magnetic (NM) materials Ru, Cr, Al, and MgO. Moreover, for NiFe layer systems, the influence of interface effects is studied by way of thickness dependent measurements of M{sub eff} and α{sub eff}. Additionally, spin pumping in NiFe/NM/Pt is investigated by means of inverse spin Hall effect (ISHE) measurements. We observe a large dependence of M{sub eff} and α{sub eff} of the NiFe films on the adjacent NM layer. While Cr and Al do not induce a large change in the magnetic properties, Ru, Pt, and MgO affect M{sub eff} and α{sub eff} in different degrees. In particular, NiFe/Ru and NiFe/Ru/Pt systems show a large perpendicular surface anisotropy and a significant enhancement of the damping. In contrast, the magnetic properties of CoFeB films do not have a large influence of the NM adjacent material and only CoFeB/Pt systems present an enhancement of α{sub eff}. However, this enhancement is much more pronounced in NiFe/Pt. By the introduction of the NM spacer material, this enhancement is reduced. Furthermore, a difference in symmetry between NiFe/NM/Pt and NiFe/NM systems in the output voltage signal from the ISHE measurements reveals the presence of spin pumping into the Pt layer in all-metallic NiFe/NM/Pt and NiFe/Pt systems.

• OSTI ID: 22402910
• Journal Information: Journal of Applied Physics, Vol. 117, Issue 16; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABSORPTION SPECTROSCOPY
ANISOTROPY
COBALT COMPOUNDS
FERROMAGNETIC RESONANCE
HALL EFFECT
INTERFACES
INTERMETALLIC COMPOUNDS
IRON
IRON BORIDES
LAYERS
MAGNESIUM OXIDES
MAGNETIC MATERIALS
MAGNETIC PROPERTIES
MAGNETIZATION
NICKEL
PLATINUM
PUMPING
RUTHENIUM
SURFACES
THIN FILMS