|
Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Science / Faculty of Science >
Peer-reviewed Journal Articles, etc >
Optical phase change in bismuth through structural distortions induced by laser irradiation
| Title: | Optical phase change in bismuth through structural distortions induced by laser irradiation |
| Authors: | Handegard, Orjan S. Browse this author | | Kitajima, Masahiro Browse this author | | Nagao, Tadaaki Browse this author →KAKEN DB |
| Keywords: | Bismuth | | phase change | | laser irradiation | | structural defects | | Raman spectroscopy |
| Issue Date: | Mar-2020 |
| Publisher: | Taylor & Francis |
| Journal Title: | Radiation effects and defects in solids |
| Volume: | 175 |
| Issue: | 3-4 |
| Start Page: | 291 |
| End Page: | 306 |
| Publisher DOI: | 10.1080/10420150.2019.1701461 |
| Abstract: | Semimetal bismuth (Bi) is known to possess a wide range of peculiar properties, owing to its unique electronic band structure. Its electronic band can easily be distorted by structural changes, and thereby undergo transitions between semimetal to either semiconductor or metal states. Utilising a focused laser beam, one can easily introduce structural defects, along with phase changes, oxidation, and morphological modifications. Confocal Raman microscopy indicated that the as-fabricated Bi droplets inhibit the Raman signal from the underlying silicon (Si) substrate. After a laser flash heating step, the intensity of Si optical phonons was strongly enhanced at the positions of Bi droplets, and exceeding the intensity from the bare Si substrate. Thus, such laser irradiating step on the Bi droplets induces an optical phase change. The optical phase change was detected as going from inhibition to strong enhancement of the underlying Si substrate Raman signal. From the observed Bi optical phonon modes (E-g and A(1g)), alterations in the Raman peaks due to laser exposure indicated that the ordered crystallinity in pristine Bi droplets became deteriorated. The effects of atomic displacements and loss of structural order in Bi droplets impacts its dielectric response. The observed Si Raman signal enhancement is similar to the surface-enhanced Raman scattering effect typically known for noble metals. |
| Rights: | This is an Accepted Manuscript of an article published by Taylor & Francis in Radiation Effects and Defects in Solids on on Published online: 30 Mar 2020, available online: https://www.tandfonline.com/doi/abs/10.1080/10420150.2019.1701461. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/80705 |
| Appears in Collections: | 理学院・理学研究院 (Graduate School of Science / Faculty of Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
|
Submitter: 長尾 忠昭
|
