| Autor: |
So, Frederick, I. Shames, Alexander, Daiki, Terada, Takuya, Genjo, Morishita, Hiroki, Izuru, Ohki, Takeshi, Ohshima, Shinobu, Onoda, Takashima, Hideaki, Takeuchi, Shigeki, Mizuochi, Norikazu, Ryuji, Igarashi, Masahiro, Shirakawa, F. Segawa, Takuya |
| Jazyk: |
angličtina |
| Rok vydání: |
2022 |
| Zdroj: |
The Journal of Physical Chemistry C. 126(11):5206-5217 |
| ISSN: |
1932-7447 |
| Popis: |
Nanodiamonds containing negatively-charged Nitrogen-Vacancy (NV-) centers are versatile room-temperature quantum sensors in a growing field of research. Yet, knowledge regarding the formation mechanism in very small particles is still limited. Here, the study was focused on the formation of the smallest NV--containing diamonds, 5 nm detonation nanodiamonds (DNDs). As a reliable method to quantify NV- centers in nanodiamonds, half-field signals in electron paramagnetic resonance (EPR) spectroscopy are recorded. By comparing the NV- concentration in a series of nanodiamonds (5 - 100 nm), it was shown that the formation process in DNDs is unique in several aspects. NV- centers in DNDs are already formed during electron irradiation, without the need for high-temperature annealing. The effect was interpreted in terms of “self-annealing”, where size and type dependent effects enable vacancy migration at lower temperature. Although NV- concentration increases with particle size, the NV- concentration in NDs surpasses that of 20 nm-sized nanodiamonds. Using Monte-Carlo simulations, we show that the higher substitutional Nitrogen concentration compensates the vacancy loss induced by the large particle surface. Upon 1.5 × 1019 e-/cm2 electron irradiation, DNDs show a 12.5-fold NV- increment with no sign of saturation. These findings can be of interest for the creation of defects in other very small semiconductor nanoparticles. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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