Theoretical investigation of electron-phonon interaction in the orthorhombic phase of Mo2C

• Published in: Journal of alloys and compounds 2019-06, Vol.788, p.842-851
• Main Authors: Karaca, E., Baǧcı, S., Tütüncü, H.M., Uzunok, H.Y., Srivastava, G.P.
• Format: Article
• Language: English
• Subjects: A. Transition metal alloys and compounds; C. Elasticity; Critical temperature; Crystal structure; D. Computer simulations; Density functional theory; Elastic properties; Electron phonon interactions; Electronic properties; Electronic structure; Electrons; Iron nitride; Mathematical analysis; Orthorhombic phase; Phonons; Plane waves; Superconductors
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2019.02.243

We have studied the structural, electronic, elastic, mechanical, vibrational and electron-phonon interaction properties of Mo2C crystallizing in the simple orthorhombic ζ-Fe2N-type crystal structure by using the generalized gradient approximation of the density functional theory and the plane wave ab initio pseudopotential method. A critical assessment of the calculated electronic structure and density of states reveals that the bonding in this material is a combination of covalent, ionic and metallic in nature. The calculated values of the second order elastic constants signal its mechanical stability. An examination of the calculated Eliashberg spectral function reveals that Mo-related phonon modes couple strongly to electrons due to the significant presence of Mo d electrons at the Fermi energy. From the integration of this spectral function, the value of average electron-phonon coupling parameter is determined to be of the intermediate strength 0.709. Finally, the value of the superconducting critical temperature is calculated to be 7.37 K, in excellent accordance with its measured value of 7.30 K. The simple orthorhombic ζ-Fe2N-type crystal structure of Mo2C superconductor. [Display omitted] •Ab initio pseudopotential method is performed to examine the physical properties of Mo2C superconductor.•The bonding in this superconductor is a combination of covalent, ionic and metallic in nature.•The calculated values of elastic constants signal the mechanical stability of this superconductor.•Mo-related phonon modes couple strongly to electrons rather than remaining phonon modes.•The calculated TC of 7.37 K consistent excellently with its measured value of 7.30 K.