https://doi.org/10.1140/epjb/e2020-10295-x
Regular Article
L21 and XA ordering effect on phase stability, electronic structure, magnetic and thermodynamic properties in Scandium-Based Full-Heusler Alloys Sc2CoZ (Z = Al, Ga, In)
1
Ecole Normale Supérieure d’Oran, BP 1063 Saim Mohamed,
Oran
31003, Algeria
2
Department of materials sciences, Sciences institute, Belhadj Bouchaib University Center, BP 284,
Ain Temouchent
46000, Algeria
3
Laboratory of Physical Chemistry of Advanced Materials, University of Djillali Liabes, BP 89,
Sidi-Bel-Abbes
22000, Algeria
a e-mail: salem.hebri@gmail.com
Received:
12
June
2020
Received in final form:
27
August
2020
Accepted:
7
October
2020
Published online: 2 December 2020
Site preference of transition metal elements habitually determined by the number of their valence electrons has been extensively used in the design of the full-Heusler alloys X2YZ. In this work, the full-Heusler materials Sc2CoZ (Z = Al, Ga, In) were investigated and the comparison between the L21 and XA types structures of those alloys were studied based on first-principles calculations. The ferromagnetic L21 structure is found to be energetically more favorable than the XA structure. The phonon dispersion curve predicts that all alloys are dynamically stable in L21 structure. The influence of atomic ordering with respect to the Wyckoff sites on the phase stability, electronic structure and magnetism were also analyzed. Nearly half-metallic behavior is observed for the L21-type. However, XA-type is nonmagnetic semiconductor. For L21-type, all alloys have a weak magnetic moment at equilibrium lattice parameter, mainly attributed to the Co atom. Thermodynamic properties of both types of structure are studied using quasi-harmonic Debye model.
Key words: Computational Methods
© EDP Sciences / Società Italiana di Fisica / Springer-Verlag GmbH Germany, part of Springer Nature, 2020