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Mechanical, electronic, thermodynamic and vibrational properties of X2MgAl (X = Sc, Ti and Y) from first principles calculations      
Yazarlar
Nihat Arıkan
Osmaniye Korkut Ata Üniversitesi, Türkiye
Selgin Al
İzmir Demokrasi Üniversitesi, Türkiye
Doç. Dr. Ahmet İYİGÖR
Kırşehir Ahi Evran Üniversitesi, Türkiye
Özet
Due to growing interest to predict and design new potential Heusler alloys by using theoretical calculations and highly functional software, research on Heusler alloys has taken great attention. From this point of view, this study considers investigation of X2MgAl (X = Sc, Ti and Y) alloys by adopting first principles calculations for the first time. A thorough investigation has been carried out to reveal these alloys' mechanical, electronic, vibrational and thermodynamic properties. It is seen that all alloys have negative formation energies as -0.278 eV/atom for Sc2MgAl, -0.058 eV/atom for Ti2MgAl and -0.304 eV/atom for Y2MgAl which indicates synthesisability and thermodynamic stability. Mechanical stability investigations based on the elastic constants of alloys have revealed that all alloys are mechanically stable. The electronic band structures of alloys demonstrate that X2MgAl (X = Sc, Ti and Y) alloys are metallic since there is no energy gap near the Fermi level. Cauchy's pressures of alloys are found as -17.791 GPa for Sc2MgAl, 31.404 GPa for Ti2MgAl and -11.759 GPa for Y2MgAl which displays that Sc2MgAl and Y2MgAl are brittle and Ti2MgAl is ductile. The phonon dispersion curves are calculated along the lines of high symmetry within the first Brillouin region. Phonon frequencies are completely positive in the full Brillouin region, which proves the dynamic stability of the L2(1) phases of these alloys. Several thermodynamic properties such as Debye entropy, temperature and vibrational free energy are also computed and analysed. Debye entropies of alloys follow Ti2MgAl > Y2MgAl > Sc2MgAl relationship.
Anahtar Kelimeler
First principle, DFT, Electronic structure, Phonon, Elastic constant
Makale Türü Özgün Makale
Makale Alt Türü SSCI, AHCI, SCI, SCI-Exp dergilerinde yayımlanan tam makale
Dergi Adı Journal of Molecular Modeling
Dergi ISSN 1610-2940
Dergi Tarandığı Indeksler SCI-Expanded
Dergi Grubu Q3
Makale Dili İngilizce
Basım Tarihi 10-2022
Cilt No 28
Sayfalar 366 /
Doi Numarası 10.1007/s00894-022-05358-7
Makale Linki http://dx.doi.org/10.1007/s00894-022-05358-7