Ferromagnetic resonance and magnetic damping in C-doped Mn₅Ge₃

Abstract

Abstract. Ferromagnetic resonance (FMR) was used to investigate the static and dynamic magnetic properties of carbon-doped Mn 5 Ge 3 (C 0.1 and C 0.2 ) thin films grown on Ge(111). The temperature dependence of magnetic anisotropy shows an increased perpendicular magneto-crystalline contribution at 80K with an in-plane easy axis due to the large shape contribution. We find that our samples show a small FMR linewidth (corresponding to an intrinsic magnetic damping parameter α=0.005), which is a measure of the spin relaxation and directly related with the magnetic and structural quality of the material. In the perpendicular-to-plane geometry, the FMR linewidth shows a minimum at around 200K for all the samples, which seems to be not correlated to the C-doping.Ferromagnetic resonance and magnetic damping in C-doped Mn 5 Ge 3 2The magnetic relaxation parameters have been determined and indicate the twomagnon scattering as the main extrinsic contribution. We observe a change in the main contribution from scattering centres in Mn 5 Ge 3 C 0.2 at low temperatures, which could be related to the minimum in linewidth.

High Curie temperature Mn5Ge3 thin films produced by non-diffusive reaction

“…Hr depends on the ferromagnetic layer T c . For example, Hr ~ 2.3 kOe was shown to correspond to T c = 315  10 K for the epitaxial MBE-mediated Mn 5 Ge 3 layer [14]. This is in agreement with the expected T c ~ 297 K of the Mn 5 Ge 3 compound, as well as with our MFM measurements ( fig.…”

“…and Hr  ~ 8.6 kOe) for x = 0.2 corresponds to T c = 450  30 K [14]. Hr // ~ 2.0, Hr  ~ 7.5, and Hr ~ 5.5 kOe in the polycrystalline Mn 5 Ge 3 layer obtained by NDR ( fig.…”

“…However, the Curie temperature (T c ) of Mn 5 Ge 3 (~ 297 K) needs to be increased in order to obtain spin current injection at temperatures higher than room temperature (RT) [5,[9][10]. Usually, this is achieved using C [7,[10][11][12][13][14] or Fe doping [15], the dopant being co-evaporated with Mn on the Ge substrate, complicating the deposition process. Furthermore, ultra-high vacuum MBE growth is not currently used in CMOS process lines, due to its significant production cost.…”

Selective modification of the unquenched orbital moment of manganese introduced by carbon dopant in epitaxial Mn5Ge3C0.2/Ge(111)Kalvig1, Jędryka2, Wójcik3 et al. 2020Phys. Rev. B9040View full textAdd to dashboardCite

“…In addition, in the pristine sample, there exists a sixfold inplane anisotropy, present also in residual form in the C-doped film. This sixfold in-plane anisotropy was macroscopically observed in the FM resonance experiment [25]. A direct carbon impact on magnetocrystalline anisotropy leads also to a strong modification of the crystal field, evidenced in our experiment by the vanishing quadrupolar splitting of the NMR line from the Mn I site.…”

Mn5Ge3C0.6 /Ge(1 1 1) Schottky contacts tuned by an n-type ultra-shallow doping layer

“…The Mn 5 Ge 3 C 0.6 thin films growth on Ge(111) was performed using the RDE method at room temperature. This method has been described and characterised elsewhere and involves the co-deposition of Ge, Mn and C atoms on Ge(111) surface at room temperature [25,26]. It ensures a very high crystalline quality of the Mn 5 Ge 3 C x thin films and a sample A sample B Figure 1.…”