Static and dynamic magnetic properties of cubic Mn-Co-Ga Heusler films

Demiray, A. S.; Kubota, Takahide; Iihama, Satoshi; Mizukami, Shigemi; Miyazaki, T.; Naganuma, Hiroshi; Oogane, Mikihiko; Ando, Yasuo

doi:10.1063/1.4864250

Cited by 3 publications

(2 citation statements)

References 18 publications

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“…The exchange stiffness was only extracted for the 80-nm-thick film, assuming that the second mode originated from a PSSW. Here, A = 16.8 pJ/m is comparable to the exchange stiffness in other Co-based Heusler compounds (4.8–31.5 pJ/m) [ 62 , 63 , 64 ]. Table 2 summarizes M eff and g for all of the investigated Co 2 MnGa films.…”

Section: Resultssupporting

confidence: 58%

Magnetic and Electronic Properties of Weyl Semimetal Co2MnGa Thin Films

et al. 2021

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Magnetic Weyl semimetals are newly discovered quantum materials with the potential for use in spintronic applications. Of particular interest is the cubic Heusler compound Co2MnGa due to its inherent magnetic and topological properties. This work presents the structural, magnetic and electronic properties of magnetron co-sputtered Co2MnGa thin films, with thicknesses ranging from 10 to 80 nm. Polarized neutron reflectometry confirmed a uniform magnetization through the films. Hard x-ray photoelectron spectroscopy revealed a high degree of spin polarization and localized (itinerant) character of the Mn d (Co d) valence electrons and accompanying magnetic moments. Further, broadband and field orientation-dependent ferromagnetic resonance measurements indicated a relation between the thickness-dependent structural and magnetic properties. The increase of the tensile strain-induced tetragonal distortion in the thinner films was reflected in an increase of the cubic anisotropy term and a decrease of the perpendicular uniaxial term. The lattice distortion led to a reduction of the Gilbert damping parameter and the thickness-dependent film quality affected the inhomogeneous linewidth broadening. These experimental findings will enrich the understanding of the electronic and magnetic properties of magnetic Weyl semimetal thin films.

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Section: Resultssupporting

confidence: 58%

Magnetic and Electronic Properties of Weyl Semimetal Co2MnGa Thin Films

et al. 2021

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“…Both resonance fields H r and linewidths ΔH increase markedly from the easy axis to the hard axis. In addition, for easy axis [110] direction, it is notable that an additional resonance mode, i.e., perpendicular standing spin wave (PSSW) mode, [42][43][44] was excited at a lower resonance field, [42,45] which may be attributed to the surface partial spin pinning affected by anisotropy field. [45][46][47] Figure 3c,d shows the frequency and angular dependence of the resonance field H r .…”

Section: Angular Dependence Of Gilbert Damping In Co 14 Fe 16 Al Filmmentioning

confidence: 99%

Colossal Gilbert Damping Anisotropy in Heusler‐Alloy Thin Films

Wang

et al. 2023

Adv Elect Materials

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Hence, it is crucial to manipulate the Gilbert damping on demand for versatile spintronic applications. Extensive efforts have been made including material optimization, [7][8][9][10][11] interface engineering, [12][13][14][15] spin torque, [16][17] and damping anisotropy. [18][19][20][21] Among these approaches, utilizing intrinsic Gilbert damping anisotropy, without requiring multiple magnetic devices or large critical current density, has attracted considerable attention. Such a method allows continuous damping manipulation via rotating the magnetization direction.Heusler compounds constitute a prominent class of magnetic materials featuring high spin polarization [22][23][24] and ultralow magnetic damping [25][26] in spintronics. Although many theoretical works [27][28][29] predict the existence of Gilbert damping anisotropy, there has been a lack of strong experimental evidence in Heusler alloys. For instance, the earlier works, such as Co 2 FeSi, [30] Co 2 MnSi, [31] and Co 2 FeAl, [25,32,33] did not provide any convincing analysis of the intrinsic damping anisotropy. At the same time, those reported effects [30][31][32][33] are too weak to develop novel functionality in spintronic devices. Hence, seeking new Heusler ingredients with significant Gilbert damping anisotropy has become a tremendous challenge. Additionally, the key mechanism behind this effect remains unexplored in Heusler alloys.In this work, we have deposited the Heusler-alloy Co 3−x Fe x Al (x = 1-2) single crystalline thin films using the molecular beam epitaxy (MBE) technique. The in-plane angular dependent ferromagnetic resonance (FMR) measurements show that the anisotropic damping exhibits fourfold symmetry and the maximal ratio of up to 1400% for the optimized sample Co 1.4 Fe 1.6 Al, which is nearly three times higher than the highest value of 420% reported in metallic ferromagnets. [34] Furthermore, according to anisotropic magnetoresistance (AMR) measurement and first-principles calculation, we ascribed such colossal anisotropy of Gilbert damping to the variation of the spin-orbit coupling (SOC). Our results help explore the larger anisotropic damping ratio in Heusler alloys and understand its mechanism for spintronic applications. Results and Discussion Anisotropic Magnetization Relaxation of Co 3−x Fe x Al FilmsHeusler alloy Co 3−x Fe x Al (x = 1-2) thin films were grown on the MgO (001) substrates by MBE. The details of structural characteristics Manipulating Gilbert damping is of critical importance in spintronic devices. Here, this work reports the damping anisotropy of Heusler-alloy Co 3−x Fe x Al single crystalline thin films using inductive ferromagnetic resonance. A colossal Gilbert damping anisotropy ratio of up to 1400%, nearly three times higher than the highest value reported among known metallic ferromagnets, is observed in the optimized sample Co 1.4 Fe 1.6 Al. The Gilbert damping anisotropy with strong fourfold symmetry is attributed to the variation of the spin-orbit coupling, which is further corroborated by the cur...

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