Electron–Phonon Coupling and Nonthermal Effects in Gold Nano-Objects at High Electronic Temperatures
Laser irradiation of metals is widely used in research and applications. In this work, we study how the material geometry affects electron–phonon coupling in nano-sized gold samples: an ultrathin layer, nano-rod, and two types of gold nanoparticles (cubic and octahedral). We use the combined tight-b...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-07-01
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| Series: | Materials |
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| Online Access: | https://www.mdpi.com/1996-1944/15/14/4883 |
| _version_ | 1797445511655981056 |
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| author | Nikita Medvedev Igor Milov |
| author_facet | Nikita Medvedev Igor Milov |
| author_sort | Nikita Medvedev |
| collection | DOAJ |
| description | Laser irradiation of metals is widely used in research and applications. In this work, we study how the material geometry affects electron–phonon coupling in nano-sized gold samples: an ultrathin layer, nano-rod, and two types of gold nanoparticles (cubic and octahedral). We use the combined tight-binding molecular dynamics Boltzmann collision integral method implemented within XTANT-3 code to evaluate the coupling parameter in irradiation targets at high electronic temperatures (up to <i>T<sub>e</sub></i>~20,000 K). Our results show that the electron–phonon coupling in all objects with the same fcc atomic structure (bulk, layer, rod, cubic and octahedral nanoparticles) is nearly identical at electronic temperatures above <i>T<sub>e</sub></i>~7000 K, independently of geometry and dimensionality. At low electronic temperatures, reducing dimensionality reduces the coupling parameter. Additionally, nano-objects under ultrafast energy deposition experience nonthermal damage due to expansion caused by electronic pressure, in contrast to bulk metal. Nano-object ultrafast expansion leads to the ablation/emission of atoms and disorders the inside of the remaining parts. These nonthermal atomic expansion and melting are significantly faster than electron–phonon coupling, forming a dominant effect in nano-sized gold. |
| first_indexed | 2024-03-09T13:27:51Z |
| format | Article |
| id | doaj.art-05b6ab1a375a40f8b22a44085e28eeca |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-09T13:27:51Z |
| publishDate | 2022-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-05b6ab1a375a40f8b22a44085e28eeca2023-11-30T21:21:30ZengMDPI AGMaterials1996-19442022-07-011514488310.3390/ma15144883Electron–Phonon Coupling and Nonthermal Effects in Gold Nano-Objects at High Electronic TemperaturesNikita Medvedev0Igor Milov1Institute of Physics, Czech Academy of Sciences, Na Slovance 1999/2, 18221 Prague, Czech RepublicAdvanced Research Center for Nanolithography (ARCNL), Science Park 106, 1098 XG Amsterdam, The NetherlandsLaser irradiation of metals is widely used in research and applications. In this work, we study how the material geometry affects electron–phonon coupling in nano-sized gold samples: an ultrathin layer, nano-rod, and two types of gold nanoparticles (cubic and octahedral). We use the combined tight-binding molecular dynamics Boltzmann collision integral method implemented within XTANT-3 code to evaluate the coupling parameter in irradiation targets at high electronic temperatures (up to <i>T<sub>e</sub></i>~20,000 K). Our results show that the electron–phonon coupling in all objects with the same fcc atomic structure (bulk, layer, rod, cubic and octahedral nanoparticles) is nearly identical at electronic temperatures above <i>T<sub>e</sub></i>~7000 K, independently of geometry and dimensionality. At low electronic temperatures, reducing dimensionality reduces the coupling parameter. Additionally, nano-objects under ultrafast energy deposition experience nonthermal damage due to expansion caused by electronic pressure, in contrast to bulk metal. Nano-object ultrafast expansion leads to the ablation/emission of atoms and disorders the inside of the remaining parts. These nonthermal atomic expansion and melting are significantly faster than electron–phonon coupling, forming a dominant effect in nano-sized gold.https://www.mdpi.com/1996-1944/15/14/4883electron–phonon couplingnanoparticleultrathin layernonthermal meltingtight-binding molecular dynamicsBoltzmann collision integrals |
| spellingShingle | Nikita Medvedev Igor Milov Electron–Phonon Coupling and Nonthermal Effects in Gold Nano-Objects at High Electronic Temperatures Materials electron–phonon coupling nanoparticle ultrathin layer nonthermal melting tight-binding molecular dynamics Boltzmann collision integrals |
| title | Electron–Phonon Coupling and Nonthermal Effects in Gold Nano-Objects at High Electronic Temperatures |
| title_full | Electron–Phonon Coupling and Nonthermal Effects in Gold Nano-Objects at High Electronic Temperatures |
| title_fullStr | Electron–Phonon Coupling and Nonthermal Effects in Gold Nano-Objects at High Electronic Temperatures |
| title_full_unstemmed | Electron–Phonon Coupling and Nonthermal Effects in Gold Nano-Objects at High Electronic Temperatures |
| title_short | Electron–Phonon Coupling and Nonthermal Effects in Gold Nano-Objects at High Electronic Temperatures |
| title_sort | electron phonon coupling and nonthermal effects in gold nano objects at high electronic temperatures |
| topic | electron–phonon coupling nanoparticle ultrathin layer nonthermal melting tight-binding molecular dynamics Boltzmann collision integrals |
| url | https://www.mdpi.com/1996-1944/15/14/4883 |
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