Electrical and Magnetic Transport Properties of Co2VGa Half-Metallic Heusler Alloy

Abstract

This study performed a systematic experimental investigation into the structural, magnetic, and transport properties of the Co2VGa Heusler alloy, which was theoretically predicted to exhibit half-metallic ferromagnetism. It has been experimentally found that the studied alloy has a relatively high-ordered L21 cubic structure at room temperature and orders ferromagnetically below ~350 K. Interestingly, by fitting the electric transport data with the properly governing equations in two different temperature regions, the two-magnon scattering process (the T9/2 dependence) appears in the temperature range from 30 to 75 K. Moreover, the magnetoresistance effect changes from a negative value to a positive value when the temperature is below 100 K. Such experimental findings provide indirect evidence that the half-metallic nature of this alloy is retained only when the temperature is below 100 K. On the other hand, the magnetic transport measurements indicate that the anomalous Hall coefficient of this alloy increases when the temperature increases and reaches a relatively high value (~8.3 μΩ·cm/T) at 300 K due to its lower saturated magnetization. By analyzing the anomalous Hall resistivity scale with the longitudinal resistivity, it was also found that the anomalous Hall effect can be ascribed to the combined effect of extrinsic skew scattering and intrinsic Berry curvature, but the latter contribution plays a dominant role.

Orbital hybridisation effects in B2 phase Cr doped Co2MnAl

“…To further understand the conduction mechanism that drives in different regions, we resorted to fit the resistivity data using different power laws. In the case of x = 0 to x = 0.10 compounds, for region II, we observe that the resistivity follows the equation [20],…”

Investigation on the crystal structure, magnetic, and electrical transport properties of magnetron sputtered Co2FeGe Heusler alloy films

“…The magnon contribution could be either due to one magnon scattering (T 2 ) or due to two magnon scattering (T 9/2 at lower temperature and T 7/2 at higher temperature). In addition to the above-mentioned contributions, spin wave excitations (T 2 at lower temperature and T at higher temperature) and Stoner fluctuations (T 2 and T 5/3 ) can also contribute to electronic resistivity [23]. Figure 3(a)-(d) shows the experimental (in black) and fitted (in red and green) ρ-T graphs for the films deposited on Si substrate at 5 mTorr pressure.…”

Influence of the Geometrical Aspect Ratio on the Magneto-Structural Properties of Co2MnSi Microwires

“…One of the most attractive materials for multiple-function applications is Co 2 -based full/half-Heusler alloys with high Curie temperatures (Tc > 1100 K), high magnetic moments, distinct electronic structures, and low Gilbert damping constants (=0.004) [4,8]. Because of their distinctive electronic band structures, some Co 2 -based full Heusler alloys also exhibit a significant anomalous Hall effect in addition to half-metallic ferromagnetism [9]. Accordingly, Co 2 -based Heusler alloys have attracted the scientific community's attention and, therefore, have been widely explored experimentally.…”