Investigations of structural and optical properties of Bi2−xCrxS3 nanocrystals embedded in host glass
| Autor: | Anielle Christine Almeida Silva, Éder V. Guimarães, R.S. Silva, Noelio O. Dantas, Hanna D. Mikhail |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Materials science
Magnetic moment Mechanical Engineering 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences 0104 chemical sciences symbols.namesake Nanocrystal Mechanics of Materials Quantum dot Chemical physics Atom symbols General Materials Science Direct and indirect band gaps Density functional theory 0210 nano-technology Raman spectroscopy Spectroscopy |
| Zdroj: | Materials Letters. 265:127430 |
| ISSN: | 0167-577X |
| DOI: | 10.1016/j.matlet.2020.127430 |
| Popis: | The optical and structural properties of Cr-doped Bi2S3 nanocrystals embedded in host glass were investigated. Transmission electron microscopy images and energy dispersive X-ray spectroscopy confirm the formation of the Bi2−xCrxS3 nanocrystals and the presence of the Bi, S and Cr elements. Raman spectroscopy reveal changes of structural crystalline in function of xCr-concentration in Bi2−xCrxS3 nanocrystals. Ultraviolet and visible spectra reveal the effects of quantum confinement with the change in size of nanocrystals. Optical properties of Cr-doped Bi2S3 nanocrystals are different in relation non-doped Bi2S3 nanocrystals. Density functional theory simulations were carried out for bulk undoped and Cr-doped Bi2S3. The unit cell volume reduces with Cr-doping, and the indirect band gap decreases from 1.17 eV (Bi2S3 undoped) to 0.67 eV for Bi2S3:CrBi1 and 0.43 eV for Bi2S3:CrBi2. For both Cr-doped structures, a spin contribution to the magnetic moment of 3.0 µB per unit cell containing one Cr atom were obtained. Within the density functional theory accuracy, these results are in agreement with the experimental results for the 3d3 high-spin state of Cr3+. |
| Databáze: | OpenAIRE |
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