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Purpose: In this paper, based on the density functional theory (DFT) and finite element method (FEM), the elastic, buckling and vibrational behaviors of the monolayer bismuthene are studied. Design/methodology/approach: The computed elastic properties based on DFT are used to develop a finite element (FE) model for the monolayer bismuthene in which the Bi-Bi bonds are simulated by beam elements. Furthermore, mass elements are used to model the Bi atoms. The developed FE model is used to compute Young's modulus of monolayer bismuthene. The model is then used to evaluate the buckling force and fundamental natural frequency of the monolayer bismuthene with different geometrical parameters. Findings: Comparing the results of the FEM and DFT, it is shown that the proposed model can predict Young's modulus of the monolayer bismuthene with an acceptable accuracy. It is also shown that the influence of the vertical side length on the fundamental natural frequency of the monolayer bismuthene is not significant. However, vibrational characteristics of the bismuthene are significantly affected by the horizontal side length. Originality/value: DFT and FEM are used to study the elastic, vibrational and buckling properties of the monolayer bismuthene. The developed model can be used to predict Young's modulus of the monolayer bismuthene accurately. Effect of the vertical side length on the fundamental natural frequency is negligible. However, vibrational characteristics are significantly affected by the horizontal side length. [ABSTRACT FROM AUTHOR]

Low temperature decomposition of ferrous martensite leads to the formation of alternate C-rich and Fe-rich domains. Although some contradictions exist in the experimental results, the C-rich domains are often supposed to be the ordered α ″ - Fe 16 C 2 phase. The aim of our theoretical study is to investigate the fundamental properties of the α ″ - Fe 16 C 2 phase and to compare it to the isomorphic known phase α ″ - Fe 16 N 2 . In this paper, we present the structural, electronic, magnetic, vibrational and elastic properties of α ″ - Fe 16 C 2 and Fe 16 N 2 phases, calculated within the formalism of the DFT theory. This study is used to discuss the relative properties and stabilities of these two phases. [ABSTRACT FROM AUTHOR]

This paper is based on the study of structural, electronic, magnetic, elastic, phonon dynamics and thermodynamic properties of d 0 half-Heusler alloys GeKZ (Z = Ca, Sr) using the Density Functional Theory (DFT) approach. The investigation is carried out using the spin-polarized calculations with pseudopotential approach using Generalized Gradient Approximation by Perdew–Burke–Ernzerhof (GGA-PBE). Both the compounds GeKCa and GeKSr are found to be structurally stable in the ferromagnetic α -phase. The electronic properties in the form of spin-polarized band-structures and density of states of the compounds GeKCa and GeKSr show that they are half-metallic in nature with a finite and large half-metallic band-gap of 0.37 eV and 0.29 eV respectively in the spin-up states and a metallic behavior in the spin-down states with 100 % spin-polarization at the Fermi-level. Integral magnetic moment of 1.00 μ B is obtained for both the compounds which is in accordance with the Slater–Pauling Rule for half-Heusler alloys. The elastic properties show that the compounds are mechanically stable following Born stability criteria for cubic compounds and are found to be ductile in nature. The compounds have also been found to be dynamically stable against lattice vibrations on the basis of phonon dispersion calculations. They have also been explored regarding their thermodynamic properties using the quasi-harmonic approximation. They are also examined for the preservation of the integral magnetic moment against the lattice compression and expansion. The observed properties points towards the suitability of these compounds in the spintronics applications. [Display omitted] [ABSTRACT FROM AUTHOR]