Competition of L21 and XA ordering in Fe2CoAl Heusler alloy: a first-principles study

Abstract

The physical properties of Fe2CoAl (FCA) Heusler alloy have been determined by means of first-principles calculations. We focus on the influence of atomic ordering, with respect to the Wyckoff sites A (0, 0, 0), B (0.25, 0.25, 0.25), C (0.5, 0.5, 0.5) and D (0.75, 0.75, 0.75), on the structural, magnetic and electronic properties in both the conventional L21 (Cu2MnAl prototype) and XA (Hg2CuTi prototype) inverse Heusler structures. Various non-magnetic and magnetic configurations are considered. Out of these, the ferromagnetic XA-I structure is found to be energetically most stable. The total magnetic moments per cell were not in agreement with the Slater-Pauling rule in any phases. Half-metallicity is not observed in any configuration. However, all the structures exhibit high magnetic moment, Curie temperature and spin polarization. The calculated values of total magnetic moment and Curie temperature (Tc) are in a close agreement with the available experimental data. The possibility of making the alloy a half metal is also discussed.

First‐Principles Investigation on Thermoelectric and Vibrational Properties of Half‐Metallic Ir2MnX (X = B, Al, Ga, In) Heusler Alloys

“…The calculated Curie temperature, T c , of an HMA is given in Table 3 , which is suitable for experimental synthesis at room temperature for Ir 2 MnAl. [ 38 ] Similarly, we have calculated the thermodynamic properties of the remaining Ir‐based compounds given in Table 3. All the compounds have the possibility of experimental synthesis at room temperature.…”

“…In addition, the computed mechanical properties of Ir 2 MnAl and Ir 2 MGa varied by only 1% from the other theoretical reports. [ 38 ]…”

Pressure dependent half-metallic ferromagnetism in inverse Heusler alloy Fe2CoAl: a DFT+U calculations

“…Ternary full-HAs crystallize in two ordered phases: Cu 2 MnAl-type with space group Fm 3m (225) 35,56 and Hg 2 CuTi-type with the F 43m (216) space group. 57,58 The former is referred to as regular/direct (L2 1 ) and the latter is inverse/indirect with XA-structure. The atomic Wyckoff positions for both the XA-phase and the L2 1 -phase of Fe 2 CoAl are tabulated in Table 1.…”

First-principles calculations and experimental studies on Co2FeGe Heusler alloy nanoparticles for spintronics applications

“…However, such studies are mostly limited to core-shell nanomaterials [7], binary alloys [8], and oxides [9]. Recently, Heusler based intermetallic compounds [10] have received a considerable attention owing to their exceptional physical properties, such as high spin polarization (P) up to 100%, half-metallic ferromagnetism (HMF), high Curie temperature (Tc) and high magnetic moment [11][12][13][14][15][16]. The readers are referred to our previous paper in order to understand the detailed mechanism of halfmetallic ferromagnetism in X2YZ type full-HAs [13].…”