The effect of martensitic phase transition from cubic to tetragonal on the physical properties of V3Si superconductor. (May 2018)

• Record Type: Journal Article
• Authors: Tütüncü, H.M.; Uzunok, H.Y.; Srivastava, G.P.; Özdemir, V.; Uǧur, G.
• Is Part Of: Intermetallics. Volume 96(2018:May)
• Page Start: 25
• Page End: 32
• Publication Date: 2018-05
• Subjects: Intermetallics -- Density functional theory, electronic structure -- Superconducting properties -- Ab–initio calculations -- Physical properties; Intermetallic compounds -- Metallography -- Periodicals; Metallic glasses -- Periodicals; Composés intermétalliques -- Métallographie -- Périodiques; 669.94
• DOI: 10.1016/j.intermet.2018.02.010
• Languages: English
• ISSNs: 0966-9795

Abstract

Abstract: We report results of ab-initio studies for the structural, electronic, lattice dynamical and electron-phonon interaction properties of cubic and tetragonal phases of V3 Si by using the plane-wave pseudopotential method, the density-functional theory, and a linear-response technique. Our total energy results propose that the martensitic transition from cubic to a tetragonal variant of the A15 structure takes place with a very little change in the unit cell volume and total energy. Thus, the electronic and lattice dynamical properties of both phases look like similar to each other. Our electron-phonon interaction calculations reveal that the phonon properties of V lattice considerably enter into electron-phonon interaction calculations due to noteworthy presence of transition metal d electrons at the Fermi level. Using the calculated value of 1.15 for the average electron-phonon coupling parameter of both phases, the superconducting critical temperature and the electronic specific heat coefficient are evaluated to be 17.3 K and 54.5 m J / ( mol K 2 ), respectively, in gratifying agreement with their measured values of 17 K and 53 m J / ( mol K 2 ) . Graphical abstract: Highlights: The electronic properties of cubic and tetragonal phases of V3 Si are examined. A feature common in their electronic structures is the flat bands near the Fermi level. Phonon calculations indicate that both phases are dynamically stable. The value of λ is found to be 1.15 for both phases. The value of Tc is found to be 17.3 K in agreement with its measured value of 17.0 K.