Two-magnon scattering by domain wall induced coupling in Co₂MnGe/Au/Py layer systems

Abstract

Sample inhomogeneities such as interface roughness, impurities, or crystal lattice dislocations can be the cause for two‐magnon scattering in ferromagnetic thin films. Using an element specific time‐resolved technique, we show experimentally that in Co2MnGe/Au/Ni81Fe19 trilayers the uniform magnetization precession in Ni81Fe19 (Py) layer can be influenced by magnetic stray fields emerging from the domain walls of micrometer size magnetic ripple domains in the Co2MnGe layer. We have found that these stray fields cause a phase shift of the transversal dynamic magnetization component of the precessional motion in the Py layer. We attribute the observed phase slip in precession to the two‐magnon scattering process.

Enhanced spin–orbit coupling in tetragonally strained Fe–Co–B films

“…In order to analyze the intrinsic contributions to the overall relaxation rate in our samples we plot the values of FMR peak-to-peak linewidth as a function of mw frequency f in figure 4. For the (Fe 0.4 Co 0.6 ) 0.9 B 0.1 system the FMR linewidth (not shown) does not exhibit a clear linear dependence on the excitation frequency pointing towards a significant contribution of twomagnon scattering to the magnetic relaxations [60] in the film with smallest crystallinity [61,62]. The solid red lines in figure 4 represent the fits to the data using equation (3) [33,38,60].…”

ALICE—An advanced reflectometer for static and dynamic experiments in magnetism at synchrotron radiation facilities

“…87 The ability of TR-XRMS to probe element specific free precessional magnetization dynamics allows studies of artificially prepared complex structures with more than one magnetic material. We have studied the free precessional dynamics of the Fe magnetic moments in Ni 81 Fe 19 alloy films (Py), 75 in spin valve type trilayers such as Co/Cu/Py, Co 2 MnGe/V/Py and Co 2 MnGe/Au/Py, 77,78,88 or Py/Cu and Py/AlO multilayer structures. 76 An interesting effect has been found by studying magnetization precessional dynamics of Py layers in the Co/Cu/Py spin valves having two different configurations of mutual orientation of magnetization in Py and Co layers: parallel (P) and antiparallel (AP).…”

“…The two magnon scattering in the Py film is only observed when the Co 2 MnGe Heusler layer is in a domain state, generating inhomogeneous stray fields from the domain walls. 78,88 Moreover, TR-XRMS was used to study the dynamics in Py/Cu and Py/AlO x multilayer systems as well as simple alloys with different stoichiometries (Fe x Ni 1−x ) and for rare-earth (Gd, Dy) doped permalloy layers. 85…”

Large enhancement of magnetic damping in the presence of domain walls in spin valves

“…Besides the spin relaxation mechanisms involved in singlelayer magnetic films, the influence of the fixed layers on the free layer magnetic damping is a very interesting issue for spin valves [10]. Several mechanisms have been proposed to describe the modulation of the free layer magnetic damping due to the interplay between the free and fixed layers [2,10,[12][13][14][15][16]. Among them, the framework of the nonlocal spin transport has been extensively investigated.…”

“…It should be pointed out that magnetostatic coupling has been considered as a mechanism of extrinsic damping in single-layer magnetic films, particularly the relevant two-magnon scattering [20][21][22]. Such an extrinsic damping mechanism has been proposed to play a significant role in spin valves when domain walls (DW) are presented in the fixed layer [13,15]. The stray fields of DW across the space layer will act on the free layer.…”