First-Principles Calculations of the Dynamical and Thermodynamic Properties of Yttrium Compounds YX (X = N, P, As and Sb)
| Autor: | Chaouche Yassine, Benkhedir Mohammed Loutfi |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Bulk modulus
Phonon Metals and Alloys chemistry.chemical_element Thermodynamics 02 engineering and technology Yttrium 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Heat capacity Lattice constant chemistry Ab initio quantum chemistry methods 0103 physical sciences Materials Chemistry Density of states Density functional theory 010306 general physics 0210 nano-technology |
| Zdroj: | Journal of Phase Equilibria and Diffusion. 37:336-344 |
| ISSN: | 1863-7345 1547-7037 |
| DOI: | 10.1007/s11669-016-0464-0 |
| Popis: | The structural, dynamical and thermodynamical properties of the yttrium pnictides YN, YP, As and YSb compounds in the NaCl (B1) stable phase and the CsCl (B2) unstable phase structures are studied by performing ab initio calculations with the help of the generalized gradient approximation (GGA). The computed lattice parameters; lattice constants, static bulk modulus and corresponding first-order pressure derivative of the bulk modulus are obtained in the two structures NaCl and CsCl and compared with other theoretical and experimental values. The transition pressure from B1 type to B2 type phases is presented and it is about 171, 72, 75 and 34 GPa for YN, YP, YAs and YSb compounds respectively. To obtain the dispersion relation curves and density of states we used the linear-response approach to the density functional theory in both structures. The values of phonon frequencies are used to obtain the thermodynamic quantities such as entropy and heat capacity as function of temperature at different pressures. |
| Databáze: | OpenAIRE |
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