Radial-tangential mode of single-wall carbon nanotubes manifested by Landau regulation: reinterpretation of low- and intermediate-frequency Raman signals
Abstract The low-frequency Raman signals of single-wall carbon nanotubes (SWNTs), appearing in the range of 100–300 cm−1, have been interpreted as radial-breathing mode (RBM) comprising pure radial Eigenvectors. Here, we report that most of the low-frequency and intermediate-frequency signals of SWN...
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Nature Portfolio
2023-03-01
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| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-023-32018-4 |
| _version_ | 1797853875134267392 |
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| author | K. P. S. S. Hembram Jin-Gyu Kim Sang-Gil Lee Jeongwon Park Jae-Kap Lee |
| author_facet | K. P. S. S. Hembram Jin-Gyu Kim Sang-Gil Lee Jeongwon Park Jae-Kap Lee |
| author_sort | K. P. S. S. Hembram |
| collection | DOAJ |
| description | Abstract The low-frequency Raman signals of single-wall carbon nanotubes (SWNTs), appearing in the range of 100–300 cm−1, have been interpreted as radial-breathing mode (RBM) comprising pure radial Eigenvectors. Here, we report that most of the low-frequency and intermediate-frequency signals of SWNTs are radial-tangential modes (RTMs) coexisting radial and tangential Eigenvectors, while only the first peak at the low-frequency side is the RBM. Density functional theory simulation for SWNTs of ~ 2 nm in diameter shows that dozens of RTMs exhibit following the RBM (~ 150 cm−1) up to G-mode (~ 1592 cm−1) in order with Landau regulation. We specify the RBM and the RTM on Raman spectra obtained from SWNTs, where both appear as prominent peaks between 149 and 170 cm−1 and ripple-like peaks between 166 and 1440 cm−1, respectively. We report that the RTMs have been regarded as RBM (~ 300 cm−1) and ambiguously named as intermediate-frequency mode (300–1300 cm−1) without assignment. The RTMs gradually interlink the RBM and the G-mode resulting in the symmetric Raman spectra in intensity. We reveal high-resolution transmission microscope evidence for a helical structure of SWNTs, informing the typical diameter of commercial SWNTs to be 1.4–2 nm. |
| first_indexed | 2024-04-09T19:56:47Z |
| format | Article |
| id | doaj.art-b940e6beffe74940bdaba5b0afe6427a |
| institution | Directory Open Access Journal |
| issn | 2045-2322 |
| language | English |
| last_indexed | 2024-04-09T19:56:47Z |
| publishDate | 2023-03-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj.art-b940e6beffe74940bdaba5b0afe6427a2023-04-03T05:25:52ZengNature PortfolioScientific Reports2045-23222023-03-011311810.1038/s41598-023-32018-4Radial-tangential mode of single-wall carbon nanotubes manifested by Landau regulation: reinterpretation of low- and intermediate-frequency Raman signalsK. P. S. S. Hembram0Jin-Gyu Kim1Sang-Gil Lee2Jeongwon Park3Jae-Kap Lee4Center for Opto-Electronic Materials and Devices, Korea Institute of Science and Technology (KIST)Center for Research Equipment, Korea Basic Science InstituteCenter for Research Equipment, Korea Basic Science InstituteDepartment of Electrical and Biomedical Engineering, University of NevadaCenter for Opto-Electronic Materials and Devices, Korea Institute of Science and Technology (KIST)Abstract The low-frequency Raman signals of single-wall carbon nanotubes (SWNTs), appearing in the range of 100–300 cm−1, have been interpreted as radial-breathing mode (RBM) comprising pure radial Eigenvectors. Here, we report that most of the low-frequency and intermediate-frequency signals of SWNTs are radial-tangential modes (RTMs) coexisting radial and tangential Eigenvectors, while only the first peak at the low-frequency side is the RBM. Density functional theory simulation for SWNTs of ~ 2 nm in diameter shows that dozens of RTMs exhibit following the RBM (~ 150 cm−1) up to G-mode (~ 1592 cm−1) in order with Landau regulation. We specify the RBM and the RTM on Raman spectra obtained from SWNTs, where both appear as prominent peaks between 149 and 170 cm−1 and ripple-like peaks between 166 and 1440 cm−1, respectively. We report that the RTMs have been regarded as RBM (~ 300 cm−1) and ambiguously named as intermediate-frequency mode (300–1300 cm−1) without assignment. The RTMs gradually interlink the RBM and the G-mode resulting in the symmetric Raman spectra in intensity. We reveal high-resolution transmission microscope evidence for a helical structure of SWNTs, informing the typical diameter of commercial SWNTs to be 1.4–2 nm.https://doi.org/10.1038/s41598-023-32018-4 |
| spellingShingle | K. P. S. S. Hembram Jin-Gyu Kim Sang-Gil Lee Jeongwon Park Jae-Kap Lee Radial-tangential mode of single-wall carbon nanotubes manifested by Landau regulation: reinterpretation of low- and intermediate-frequency Raman signals Scientific Reports |
| title | Radial-tangential mode of single-wall carbon nanotubes manifested by Landau regulation: reinterpretation of low- and intermediate-frequency Raman signals |
| title_full | Radial-tangential mode of single-wall carbon nanotubes manifested by Landau regulation: reinterpretation of low- and intermediate-frequency Raman signals |
| title_fullStr | Radial-tangential mode of single-wall carbon nanotubes manifested by Landau regulation: reinterpretation of low- and intermediate-frequency Raman signals |
| title_full_unstemmed | Radial-tangential mode of single-wall carbon nanotubes manifested by Landau regulation: reinterpretation of low- and intermediate-frequency Raman signals |
| title_short | Radial-tangential mode of single-wall carbon nanotubes manifested by Landau regulation: reinterpretation of low- and intermediate-frequency Raman signals |
| title_sort | radial tangential mode of single wall carbon nanotubes manifested by landau regulation reinterpretation of low and intermediate frequency raman signals |
| url | https://doi.org/10.1038/s41598-023-32018-4 |
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