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

Abstract

We report the electronic and magnetic properties along with the Curie temperature (TC) of the inverse full Heusler alloy (HA) Fe2CoAl obtained using the first-principles computational method.

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

“…The lattice parameter a obtained from Rietveld refinement of the XRD patterns of the nanoparticles (see Table 1) was found to be within the range of previously published theoretical and experimental values of 5.697 to 5.766 Å. 12,14,16,18,19,[21][22][23][25][26][27][28]30 Scherrer's equation 46 was used to estimate the average crystallite size (D v ) of the prepared Fe 2 CoAl nanoparticles as listed in Table 1. D v exhibited a dependence on the heat treatment temperature and time, as expected.…”

“…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.…”

“…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. The discrepancies in the previous results inspired us to investigate the DOS of the Fe 2 CoAl Heusler alloy.…”

“…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.…”

Feature‐rich structural, electronic, magnetic and optical properties of the fluorine‐ and nitrogen‐incorporated CaF2 compound

“…To examine the structural stability of studied materials, the cohesive energy E c is used being calculated as follows [22]: herein, the energy of isolated Ca, F and X (F, N) are represented by E a ( Ca ), E a ( F ) and E a ( X ), respectively. According to our simulations, E c value of CaF 3 and CaF 2 N are −4.352 and −4.069 (eV/atoms), respectively.…”