Site preferences of Fe2CoAl Heusler alloy: A first-principles DFT study

Single-Domain Fe2CoAl Nanoparticles and Their Crystallite Size-Dependent Properties

“…Figure shows the TDOS as well as atom-resolved partial density of states (PDOS) for the elements Fe, Co, and Al for both L 2 1 and X -type structures around E F . The results show close similarity to the previous DOS calculated by Coelho et al and Ahmad et al, , which clarifies that Fe 2 CoAl with neither an L 2 1 nor an X -type structure shows complete half metallicity. The valence band of Fe 2 CoAl contains contributions from both the majority and minority spins in the DOS plots, but the conduction band has large contributions just from the minority spins.…”

“…This behavior is in line with the previous reports on bulk Fe 2 CoAl , and Fe 2 CoAl nanoparticles . The experimental saturation magnetization ( M s ) values listed in Table of the synthesized nanoparticles are comparable to the previously reported theoretical values ranging from 3.981 to 5.33 μ B /f.u., ,− , experimental M s values for bulk Fe 2 CoAl range from 4.4 to 5; ,,− thin film ∼5.3 μ B /f.u . nanowires range from 4.5 to 5.1 μ B /f.u., and nanoparticles range from 4.5 to 5.17 μ B /f.u. , Furthermore, the evidence in favor of the formation of an inverse Heusler alloy structure also comes from the fact that the experimental M s of the three Fe 2 CoAl nanoparticles (see Table ) are closer to the theoretical M t of the X -type structure than L 2 1 type structure.…”

“…Siakeng et al explored DOS for Fe 2 CoAl alloy with and without incorporating the Hubbard parameter U and declared it to be a non-half metal in both cases. Ahmad et al , on the one hand, claimed the material to be non-half metal and, on the other hand, declared it to have a high spin polarization of 78% . Rai et al found a pseudo band gap just above the Fermi level ( E F ) in the spin-down channel by incorporating U in their calculations and showed that this gap could be tuned toward E F by applying pressure.…”

“…Bulk Fe 2 CoAl alloy was first prepared by Grover et al in 1980 while substituting Co in Fe 3 Al alloy. After their report on its high T C and M s , its structural, magnetic, electronic, thermoelectric, thermodynamic, mechanical, elastic, spectroscopic, and half-metallic properties were explored in the bulk form using both theoretical − and experimental ,,− techniques. There are also some attempts to synthesize this alloy in thin film ,, and nanofiber forms.…”

Effect of L21 and XA ordering on phase stability, half-metallicity and magnetism of Co2FeAl Heusler alloy: GGA and GGA + U approach

“…Xiaotian Wang et al [25], reported the effect of L21 and XA ordering on Hafnium-based full-Heusler alloys and found that all of them were likely to stabilize in L21-type structure. We studied Fe2CoAl Heusler alloy and found that XA ordered structure was much more stable than the regular L21 structure [26,27]. The comprehensive theoretical reports are available on L21 ordered Co2FeAl Heusler alloy [28][29][30][31][32][33][34].…”