Structural and magnetic properties in the Heusler compounds Co_3−x Fe _x Al thin films

Abstract

The structural and magnetic properties are important parameters for spintronic applications of Heusler compounds. The Co2FeAl and CoFe2Al alloys are considered as the representatives of the regular and inverse Heusler structure, respectively. Here, we present a systematic study of the structural and magnetic properties of Co3-xFexAl (x = 1 ~ 2) Heusler thin films grown on MgO (001) substrates. The lattice parameters and magnetic properties, such as magnetic coercivity, saturated moment and four-fold magnetic anisotropy constant, display different change trends in the Co-rich and Fe-rich regions, which suggest that magnetic properties have relevance to the Heusler structures. Our findings give a better understanding of the Heusler structures and magnetic properties, which is helpful for developing spintronic applications.

Enhanced Luminescence of Dye-Decorated ZIF-8 Composite Films via Controllable D–A Interactions for White Light Emission

“…The peaks at ∼995 and ∼1175 cm –1 were corresponding to CC–N twisting and C–N bending vibration, respectively. The peak at ∼1015 cm –1 belonged to C–H out-of-plane bending vibration of CH 3 . , Moreover, a broad absorption band at the range of 3200–2200 cm –1 indicated the existence of N–H stretching vibration due to protonated imidazole and the peak at ∼3400 cm –1 was associated with O–H stretching vibration. − Additionally, the peak (1591 cm –1 ) with the highest relative intensity was attributed to CC/CN or CO stretching vibration due to the presence of conjugated structures in Hmim or H 3 BTC ligands . These results indicated that ZIF-8 frameworks with protonated imidazole structures have been formed (Figure ).…”

Colossal Gilbert Damping Anisotropy in Heusler‐Alloy Thin Films

“…Third, the global next‐nearest‐neighbor Co–Fe interaction is likely to be responsible for the SOC anisotropy, [ 28 ] which can be influenced by the Co(4c)–Fe(4d) disorder. This disorder is higher in the intermediate composition of this series, [ 35 ] which can understand the composition‐dependent Gilbert damping anisotropy. However, further theoretical analysis is greatly desirable.…”

“…The Co 3− x Fe x Al lattice structure rotates by 45° relative to the MgO substrate. From the previous work, [ 35 ] the easy axis is parallel to the 〈110〉 directions while the hard axis lies in 〈100〉 directions. Figure 3b illustrates the angular‐dependent FMR spectra of the Co 1.4 Fe 1.6 Al film for φ H from 0° to 90° at a frequency of 18 GHz.…”

“…The microstructural characterization, including surface morphology and the crystal structure, has been studied in the previous work. [ 35 ]…”

“…[6] have been demonstrated in our previous work. [35] The anisotropic damping constants were measured using coplanar waveguide-based differential FMR. As shown in Figure 1a, the typical (derivative) FMR absorption spectra were obtained at a frequency of 14 GHz for all the samples with the magnetic field along [110] and [100] orientations and can be well-fitted by a sum of symmetric and antisymmetric Lorentzian derivatives [36] ( ) ( ) ( )…”