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Ab initio lattice dynamics of Ni2MnX X Sn Sb magnetic shape memory alloys       
Yazarlar (2)
Savaş Ağduk
Karabük Üniversitesi, Türkiye
Prof. Dr. Gökhan GÖKOĞLU Prof. Dr. Gökhan GÖKOĞLU
Karabük Üniversitesi, Türkiye
Devamını Göster
Özet
In this study, we present the results of first principles calculations of elastic constants and phonon properties of nickel-manganese based magnetic shape memory compounds Ni2MnSn and Ni2MnSb in stoichiometric composition. The plane wave basis sets and pseudopotential method within spin-polarized generalized gradient approximation (σ-GGA) scheme of the density functional theory is applied. In investigation of the phonon dispersion spectra, linear response technique of the Density Functional Perturbation Theory is used. Phonon softening is observed in dispersion spectra at the transverse acoustic mode (TA2) in [ζ ζ 0] direction as an indication of the structural instability of these systems to shear deformation. The vibrational instability of Ni2MnSb system is larger than that of Ni2MnSn yielding negative phonon frequencies. This vibrational anomaly is also verified by the low shear modulus and large elastic anisotropy ratio. The minority spin Fermi surfaces of both systems exhibit strong nesting features. © 2011 Elsevier B.V. All rights reserved.
Anahtar Kelimeler
Computer simulations | Elasticity | Magnetically ordered materials | Phonons
Makale Türü Özgün Makale
Makale Alt Türü SSCI, AHCI, SCI, SCI-Exp dergilerinde yayımlanan tam makale
Dergi Adı JOURNAL OF ALLOYS AND COMPOUNDS
Dergi ISSN 0925-8388 Wos Dergi Scopus Dergi
Dergi Tarandığı Indeksler SCI-Expanded
Dergi Grubu Q1
Makale Dili İngilizce
Basım Tarihi 01-2012
Cilt No 511
Sayı 1
Sayfalar 9 / 13
Doi Numarası 10.1016/j.jallcom.2011.08.092
Makale Linki http://linkinghub.elsevier.com/retrieve/pii/S0925838811017798