The absence of a cheap and easily scalable synthesis technique for nitrogen-vacancy (NV) centers enriched nanodiamonds (NDs) is a critical factor for the development of devices based on this very peculiar nanoparticle. Indeed, the combination between the unique NV fluorescence properties and NDs characteristics allow to obtain a tool having quantum sensing capabilities, with nanometric spatial resolution, which is able to operate in a wide range of temperature, pressures and in harsh chemical conditions. NVenriched NDs applications in nanothermometry, nanomagnetometry and in bio-imaging have already been reported. However, most of the standard fluorescent NDs production techniques present common drawbacks: poor control in NDs size distribution and in nitrogen concentration, as well as the need of post-synthesis process to clean the NDs surface from impurities and to increase the NV density. In this thesis, an alternative method for fluorescent NDs synthesis based on pulsed laser ablation (PLA) of graphite is demonstrated. After the introductory chapters on NV-centers physics and NDs properties (Chapter 2 and 3), the demonstration that PLA is a viable route for synthesis of NDs is given in Chapter 4. In particular, PLA of graphite and of diamond-like carbon is performed in water. Here, a thermodynamic model taking into account the peculiar physical processes occurring during PLA is developed to explain NDs formation. Then, synthesis of NV-enriched NDs is demonstrated through PLA of graphite in a nitrogen atmosphere (Chapter 5) and in liquid nitrogen (Chapter 6). In both chapters, the thermodynamic model is adapted to explain diamond phase formation in a gaseous environment and in a cryogenic liquid. Furthermore, NV centers optical properties are fully characterized with optically detected magnetic resonance (ODMR) spectroscopy. Finally, in Chapter 7, fluorescent NDs are produced by laser ablation of N-doped graphite in water. This particular target is then used for a quantitative comparison between the other fluorescent NDs laser-synthesis, with the aim of establishing in which condition the highest NV-center formation efficiency is achieved.
Laser-synthesis and optical functionalization of NV-fluorescent nanodiamonds for quantum sensing applications / Basso, Luca. - (2020 Jan 24), pp. 1-127.
|Titolo:||Laser-synthesis and optical functionalization of NV-fluorescent nanodiamonds for quantum sensing applications|
|Anno di pubblicazione:||2020-01-24|
|Struttura:||Dipartimento di Fisica|
|Corso di dottorato:||Physics|
|Supervisore aggiunto/Correlatore esterno:||Correlatore esterno: A. Bifone|
|Tesi in cotutela:||sì|
|Paese e nome dell'Istituzione/ente esterno in caso di cotutela o collaborazioni internazionali:||ITALIA|
|Settore Scientifico Disciplinare:||Settore FIS/03 - Fisica della Materia|
Settore FIS/01 - Fisica Sperimentale
|Digital Object Identifier (DOI):||10.15168/11572_250439|
|Appare nelle tipologie:||08.1 Tesi di dottorato (Doctoral Thesis)|