Nanosecond magnetic relaxation processes in ultrathin metallic films prepared by MBE

Urban, R.; Heinrich, B.; Woltersdorf, Georg; Ajdari, K; Myrtle, K.; Cochran, J. F.; Rozenberg, E.

doi:10.1103/physrevb.65.020402

Cited by 51 publications

(20 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…15͒ has shown that additional FMR line broadening could be described by a two-magnon scattering mechanism. 18 The in-plane angular dependence of ⌬H was found to be primarily isotropic, indicating that the film magnetic inhomogeneities have a strong isotropic distribution independent of the orientation of the magnetization with respect to the crystallographic axes. However, ⌬H had also a noticeable fourfold anisotropy with the maximum ⌬H, aligned with the ͗110͘, crystallographic axis.…”

Section: B Magnetic Propertiesmentioning

confidence: 92%

Structural and magnetic properties of NiMnSb/InGaAs/InP(001)

Koveshnikov

Woltersdorf

Liu

et al. 2005

Journal of Applied Physics

Self Cite

View full text Add to dashboard Cite

The structural and magnetic properties of NiMnSb films, 5-120 nm thick, grown on InGaAs/ InP͑001͒ substrates by molecular-beam epitaxy, were studied by x-ray diffraction, transmission electron microscopy ͑TEM͒, and ferromagnetic resonance ͑FMR͒ techniques. X-ray diffraction and TEM studies show that the NiMnSb films had the expected half-Heusler structure, and films up to 120 nm were pseudomorphically strained at the interface, greater than the critical thickness for this system, about 70 nm ͑0.6% mismatch to InP͒. No interfacial misfit dislocations were detected up to 85 nm, however, relaxation in the surface regions of films thicker than 40 nm was evident in x-ray reciprocal space maps. TEM investigations show that bulk, planar defects are present beginning in the thinnest film ͑10 nm͒. Their density remains constant but they gradually increase in size with increasing film thickness. By 40 nm these defects have overlapped to form a quasicontinuous network aligned closely with ͗100͘ in-plane directions. The associated strain fields and or compositional ordering from these defects introduced a reduction in crystal symmetry that influenced the magnetic properties. The in-plane and perpendicular FMR anisotropies are not well described by bulk and interface contributions. In thick films, the in-plane uniaxial and fourfold anisotropies increased with increasing film thickness. The lattice defects resulted in a large extrinsic magnetic damping caused by two-magnon scattering, an increase in the coersive field with increasing film thickness, and a lower magnetic moment ͑3.6 Bohr magnetons͒ compared to the expected value for the bulk crystals ͑4 Bohr magnetons͒.

show abstract

Section: B Magnetic Propertiesmentioning

confidence: 92%

Structural and magnetic properties of NiMnSb/InGaAs/InP(001)

Koveshnikov

Woltersdorf

Liu

et al. 2005

Journal of Applied Physics

Self Cite

View full text Add to dashboard Cite

show abstract

“…This behavior is a hallmark of two magnon scattering. 8 In the perpendicular configuration no magnons have the precessional frequency equal to that of the FMR mode ͑applied microwave angular frequency ͒, and consequently two magnon scattering is absent. It follows that the additional FMR line broadening in the NiMnSb films is caused by two magnon scattering relaxation.…”

Section: Magnetic Dampingmentioning

confidence: 99%

“…This was found to be a common feature of two magnon scattering in recently studied systems. 8,11 ͑ii͒ A large angle independent contribution ⌬H 0 indicates that thick NiMnSb films are affected by a sizeable isotropic in-plane lattice disorder.…”

Section: Magnetic Dampingmentioning

confidence: 99%

Magnetic properties of NiMnSb(001) films grown on InGaAs/InP(001)

Heinrich

Woltersdorf

Urban

et al. 2004

Journal of Applied Physics

Self Cite

View full text Add to dashboard Cite

NiMnSb half Heusler alloy films were prepared by molecular beam epitaxy ͑MBE͒ on InP͑001͒. The dc and rf magnetic properties were investigated by ferromagnetic resonance ͑FMR͒. The effective uniaxial anisotropy fields increased with increasing film thickness and reached nonzero asymptotic values. FMR linewidths rapidly increased with the film thickness due to the presence of two magnon scattering. Bulklike uniaxial anisotropies and two magnon scattering were caused by a self-assembled network of lattice defects. Gilbert damping parameter and spectroscopic g factor were found to be 3.1ϫ10 7 and 2.03, respectively, indicating a weak role of spin orbit interaction.

show abstract

“…The static interlayer exchange coupling vanishes in our samples due to interface roughness on a length scale of a mere 10 ML (2 nm). One should point out that when the N metal spacer thickness starts to be comparable to the spin diffusion length then the N spacer absorbs a part of the spin current [23,24]. The quantitative comparison with predictions of the spin pumping theory is very favorable.…”

Section: Discussion Of the Resultsmentioning

confidence: 99%

Role of Spin Momentum Current in Magnetic Non-Local Damping of Ultrathin Film Structures

2002

Self Cite

View full text Add to dashboard Cite

Non-local damping was investigated by Ferromagnetic Resonance (FMR) using ultrathin magnetic single and double layer structures prepared by Molecular Beam Epitaxy (MBE). The double layer structures show magnetic damping which is caused by spin transport across a normal metal spacer (N). In double layer structures a thin Fe layer, Fl, was separated from a thick Fe layer, F2, by a Au(001) spacer. The interface magnetic anisotropies separated the FMR fields of F1 and F2 by a big margin allowing one to investigate FMR in F1 while F2 had a negligible angle of precession, and vice versa. The Fe films in magnetic double layers acquire non-local interface Gilbert damping. It will be shown that the precessing magnetic moments act as spin pumps and spin sinks. This concept was tested by investigating the FMR linewidth around an accidental crossover of the resonance fields for the layers F1 and F2. There is another possible mechanism for non-local damping which is based on a "breathing Fermi surface" of the spacer. The temperature dependence of the non-local damping indicates that this mechanism is weak in Au spacers. Surprisingly the Au spacer acts as an additional impedance for the spin pump mechanism. Finally, it will be shown that electron-electron correlations in a Pd spacer can lead to a significant enhancement of the non-local damping.

show abstract

Nanosecond magnetic relaxation processes in ultrathin metallic films prepared by MBE

Cited by 51 publications

References 19 publications

Structural and magnetic properties of NiMnSb/InGaAs/InP(001)

Structural and magnetic properties of NiMnSb/InGaAs/InP(001)

Magnetic properties of NiMnSb(001) films grown on InGaAs/InP(001)

Role of Spin Momentum Current in Magnetic Non-Local Damping of Ultrathin Film Structures

Contact Info

Product

Resources

About