Structural, lattice dynamics and thermodynamic properties of GaAs1-xPx from first-principles calculations
| Autor: | Yanjun Liang, Xiaofeng Tian, You Yu, Jiang Deng, Xianggang Kong, Yanhong Shen |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Materials science
Internal energy Condensed matter physics Phonon Mechanical Engineering Alloy Metals and Alloys 02 engineering and technology engineering.material 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Brillouin zone symbols.namesake Transverse plane Mechanics of Materials Ionic strength Helmholtz free energy Materials Chemistry symbols engineering Wave vector 0210 nano-technology |
| Zdroj: | Journal of Alloys and Compounds. 817:152733 |
| ISSN: | 0925-8388 |
| Popis: | The structural, lattice dynamics and thermodynamic properties of GaAs1-xPx with different concentration of the components have been investigated via density functional perturbation theory. The results of equilibrium lattice parameters of GaAs1-xPx indicate that our calculated values are relatively in good agreement with the available experimental and theoretical results. The calculated phonon-dispersion curves of GaAs1-xPx along high symmetry lines in the Brillouin zone display a significant hardening as the concentration of x is enhanced. Besides broadening phonon states under the definite wave vector, GaAs1-xPx alloy system expands the optic branches and raises the longitudinal modes (LO) more than the transverse modes (TO) with the elevation of the concentration of x. The LO-TO splitting degree at Γ-point reveals that the ionic strength of GaAs1-xPx will increase with the raise of the concentration of x. Moreover, using the calculated phonon density of states, the thermodynamic properties of GaAs1-xPx including the constant-volume specific heat Cv, the internal energy △E, the Helmholtz free energy △F and the entropy S are calculated within the harmonic approximation. |
| Databáze: | OpenAIRE |
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