Effects of vacancy defects on vibrational properties of Ni–Al
The phonon spectra of Ni, Al, and NiAl, as well as their electronic characteristics, are investigated using density functional theory and density functional perturbation theory. Our research on phonon dispersion has concentrated on every high symmetry point of NiAl, both with and without defects. Th...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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AIP Publishing LLC
2023-10-01
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| Series: | AIP Advances |
| Online Access: | http://dx.doi.org/10.1063/5.0171276 |
| _version_ | 1797634163120013312 |
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| author | Saran Lamichhane Mahesh Giri Narayan Prasad Adhikari |
| author_facet | Saran Lamichhane Mahesh Giri Narayan Prasad Adhikari |
| author_sort | Saran Lamichhane |
| collection | DOAJ |
| description | The phonon spectra of Ni, Al, and NiAl, as well as their electronic characteristics, are investigated using density functional theory and density functional perturbation theory. Our research on phonon dispersion has concentrated on every high symmetry point of NiAl, both with and without defects. The phonon gap of NiAl is measured to be 1.78 THz between the lowest value of the optical branch and the top bound of the acoustic branch. The NiAl supercell with a center Al vacancy was built to investigate the effects of defects on its vibrational characteristics. The phonon gap of a NiAl crystal at the center of the Brillouin zone with no defect is calculated to be 1.06 THz. This value of the phonon gap is affected by the Al vacancy defect and decreases by 7.67%. The development of phonon spectrum is investigated using electronic structure and properties. The majority of free electrons accumulated at the Fermi level contribute to promoting the vibration. The importance of a heavier element in a compound has also been explored in terms of gap tuning. Reduced thermal conductivity by narrowing the gap between optical and acoustic modes raises the figure of merit (zT) value, which improves the thermoelectric energy conversion efficiency. |
| first_indexed | 2024-03-11T12:03:40Z |
| format | Article |
| id | doaj.art-6efd197698014397a5e5f4e93d6cf222 |
| institution | Directory Open Access Journal |
| issn | 2158-3226 |
| language | English |
| last_indexed | 2024-03-11T12:03:40Z |
| publishDate | 2023-10-01 |
| publisher | AIP Publishing LLC |
| record_format | Article |
| series | AIP Advances |
| spelling | doaj.art-6efd197698014397a5e5f4e93d6cf2222023-11-07T17:47:00ZengAIP Publishing LLCAIP Advances2158-32262023-10-011310105018105018-610.1063/5.0171276Effects of vacancy defects on vibrational properties of Ni–AlSaran LamichhaneMahesh GiriNarayan Prasad AdhikariThe phonon spectra of Ni, Al, and NiAl, as well as their electronic characteristics, are investigated using density functional theory and density functional perturbation theory. Our research on phonon dispersion has concentrated on every high symmetry point of NiAl, both with and without defects. The phonon gap of NiAl is measured to be 1.78 THz between the lowest value of the optical branch and the top bound of the acoustic branch. The NiAl supercell with a center Al vacancy was built to investigate the effects of defects on its vibrational characteristics. The phonon gap of a NiAl crystal at the center of the Brillouin zone with no defect is calculated to be 1.06 THz. This value of the phonon gap is affected by the Al vacancy defect and decreases by 7.67%. The development of phonon spectrum is investigated using electronic structure and properties. The majority of free electrons accumulated at the Fermi level contribute to promoting the vibration. The importance of a heavier element in a compound has also been explored in terms of gap tuning. Reduced thermal conductivity by narrowing the gap between optical and acoustic modes raises the figure of merit (zT) value, which improves the thermoelectric energy conversion efficiency.http://dx.doi.org/10.1063/5.0171276 |
| spellingShingle | Saran Lamichhane Mahesh Giri Narayan Prasad Adhikari Effects of vacancy defects on vibrational properties of Ni–Al AIP Advances |
| title | Effects of vacancy defects on vibrational properties of Ni–Al |
| title_full | Effects of vacancy defects on vibrational properties of Ni–Al |
| title_fullStr | Effects of vacancy defects on vibrational properties of Ni–Al |
| title_full_unstemmed | Effects of vacancy defects on vibrational properties of Ni–Al |
| title_short | Effects of vacancy defects on vibrational properties of Ni–Al |
| title_sort | effects of vacancy defects on vibrational properties of ni al |
| url | http://dx.doi.org/10.1063/5.0171276 |
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