Electronic Structure, Mechanical and Dynamical Stability of Hexagonal Subcarbides M2C (M = Tc, Ru, Rh, Pd, Re, Os, Ir, and Pt): Ab Initio Calculations
| Autor: | I. R. Shein, D.V. Suetin |
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| Rok vydání: | 2018 |
| Předmět: |
010302 applied physics
Materials science Solid-state physics Thermodynamics 02 engineering and technology Electronic structure 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Heat capacity Poisson's ratio Electronic Optical and Magnetic Materials Shear modulus symbols.namesake Ab initio quantum chemistry methods 0103 physical sciences Compressibility symbols 0210 nano-technology Debye model |
| Zdroj: | Physics of the Solid State. 60:213-224 |
| ISSN: | 1090-6460 1063-7834 |
| DOI: | 10.1134/s1063783418020282 |
| Popis: | Ab initio calculations were used to study the properties of a series of hexagonal (Fe2N-like) subcarbides M2C, where M = Tc, Ru, Rh, Pd, Re, Os, Ir, and Pt, and to calculate their equilibrium structural parameters, electronic properties, phase stability, elastic constants, compression modulus, shear modulus, Young’s modulus, compressibility, Pugh’s indicator, Poisson ratio, elastic anisotropy indices, and also hardness, Debye temperature, sound velocity, and low-temperature heat capacity. It is found based on these results that all the subcarbides are mechanically stable; however, their formation energies Eform are positive with respect to a mixture of d-metal and graphite. In addition, the calculation of the phonon spectra of these subcarbides shows the existence of negative modes, which indicates their dynamical instability. Thus, a successful synthesis of these subcarbides at normal conditions is highly improbable. |
| Databáze: | OpenAIRE |
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