Structural, Electronic, Mechanical and Thermodynamic Properties of Half-Metallic Rh 2FeZ (Z = Ga, In) Full Heusler Compounds from First Principles

2020 ◽  
Author(s):  
O. E. Osafile ◽  
J. O. Umukoro
2021 ◽  
Vol 19 (3) ◽  
pp. 167-180
Author(s):  
O.E. Osafile ◽  
J.O. Umukoro

We report on the structural, electronic, mechanical, and thermodynamic properties of Rh2FeGa and Rh2FeIn full Heusler alloys from first principles. Results for the structural analysis establishes structural stability with a negative formation energy of -0.2175 eV and -0.2082 eVfor Rh2FeGa and Rh2FeIn, respectively. The lattice constants and electronic properties compare favorably with reports from existing  literature. The compounds are both anisotropic and mechanically stable, having checked out with the Born and Huang criteria. Rh2FeIn alloy is more ductile, yet, harder, and stiffer compared to its Rh2FeGa counterpart. The Debye temperatures of 400.124 K and 267. 738 K recorded for Rh2FeGa and Rh2FeIn, respectively, is consistent with the expectation that the main group element's atomic size has an inverse relationship with the Debye temperature. Therefore, indium with the larger atomic size has a lesser Debye temperature. Both compounds obey the Dulong-Petit limit at temperatures between 400 K and 500 K. The specific heat capacity at constant volume 𝐶𝜐 of 96.5 𝐽 𝑚𝑜𝑙−1𝐾−1 and 98 𝐽 𝑚𝑜𝑙−1𝐾 −1 for Rh2FeIn and Rh2FeGa alloys suggests thermodynamic stability of the compounds at moderate  temperatures. Keywords: Density functional theory; Density functional perturbation theory; Half-Heusler compounds; Mechanical Properties;  Thermodynamic properties.


2021 ◽  
Vol 24 (2) ◽  
pp. 23602
Author(s):  
A. Boughena ◽  
S. Benalia ◽  
O. Cheref ◽  
N. Bettahar ◽  
D. Rached

Topological nontrivial nature are the latest phases to be discovered in condensed matter physics with insulating bulk band gaps and topologically protected metallic surface states; they are one of the current hot topics because of their unique properties and potential applications. In this paper, we have highlighted a first-principles study of the structural stability and electronic behavior of the Na2AgX (X = As, Sb and Bi) full Heusler compounds, using the Full-Potential Linear Muffin-Tin Orbital (FP-LMTO) method. We have originated that the Hg2CuTi structure is appropriate in all studied materials. The negative values of the calculated formation energies mean that these compounds are energetically stable. The band structure is studied for the two cases relating the existence and the absence of spin-orbital couplings, where all materials are shown to be topologically non-trivial compounds. Spin orbital couplings were noticed to have no significant effect on the electronic properties such as the topological order.


RSC Advances ◽  
2020 ◽  
Vol 10 (73) ◽  
pp. 44633-44640
Author(s):  
D. P. Rai ◽  
Lalrinkima ◽  
Lalhriatzuala ◽  
L. A. Fomin ◽  
I. V. Malikov ◽  
...  

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.


2019 ◽  
Vol 6 (9) ◽  
pp. 191007 ◽  
Author(s):  
Tie Yang ◽  
Liyu Hao ◽  
Rabah Khenata ◽  
Xiaotian Wang

The structural competing and atomic ordering of the full Heusler compounds Fe 2 NiSi and Ni 2 FeSi under uniform and tetragonal strains have been systematically studied by the first-principles calculation. Both Fe 2 NiSi and Ni 2 FeSi have the XA structure in cubic phase and they show metallic band structures and large magnetic moments (greater than 3 μ B ) at equilibrium condition. Tetragonal distortion can further decrease the total energy, leading to the possible phase transformation. Furthermore, different atom reordering behaviours have been observed: for Fe 2 NiSi, atoms reorder from cubic XA-type to tetragonal L1 0 -type; for Ni 2 FeSi, there is only structural transformation without atom reordering. The total magnetic moments of Fe 2 NiSi and Ni 2 FeSi are mainly contributed by Fe atoms, and Si atom can strongly suppress the moments of Fe atoms when it is present in the nearest neighbours of Fe atoms. With the applied strain, the distance between Fe and Si atoms play an important role for the magnetic moment variation of Fe atom. Moreover, the metallic band nature is maintained for Fe 2 NiSi and Ni 2 FeSi under both uniform and tetragonal strains. This study provides a detailed theoretical analysis about the full Heusler compounds Fe 2 NiSi and Ni 2 FeSi under strain conditions.


2016 ◽  
Vol 29 (9) ◽  
pp. 2225-2233 ◽  
Author(s):  
Salah Khenchoul ◽  
Abdelnasser Guibadj ◽  
Brahim Lagoun ◽  
Abdelhakim Chadli ◽  
Said Maabed

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