The effect of martensitic phase transition from cubic to tetragonal on the physical properties of V3Si superconductor


Tutuncu H. M. , Uzunok H. Y. , Srivastava G. P. , ÖZDEMİR V. , UĞUR G.

INTERMETALLICS, vol.96, pp.25-32, 2018 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 96
  • Publication Date: 2018
  • Doi Number: 10.1016/j.intermet.2018.02.010
  • Title of Journal : INTERMETALLICS
  • Page Numbers: pp.25-32
  • Keywords: Intermetallics, Density functional theory, electronic structure, Superconducting properties, Ab-initio calculations, Physical properties, EG OPTICAL PHONON, RAMAN-SCATTERING, ELECTRONIC-STRUCTURE, HEAT-CAPACITY, TUNNELING ALPHA-2F(OMEGA), BAND-STRUCTURE, FERMI-SURFACE, X-RAY, NB3SN, TEMPERATURE

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 V3Si 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 mJ/(molK(2)), respectively, in gratifying agreement with their measured values of 17 K and 53 mJ/(molK(2)).