Surface Modifications of Detonation Nanodiamonds Probed by Multiwavelength Raman Spectroscopy

Detonation nanodiamonds (DND) with different surface chemical and structural features were characterized using multiwavelength Raman analysis, from deep UV to more conventional visible wavelengths. In particular, effects of DND surface modifications induced by annealing (air or vacuum) or by hydrogen microwave plasma on the line shape of their corresponding Raman spectra were investigated. Indeed, the different surface treatments led to specific surface terminations and/or different shell structures or surface reconstructions. In addition, annealing treatments in air or hydrogen have also been performed along with in situ Raman spectroscopy measurements. This original combination allows a better understanding of the corresponding surface modifications. The effects of the different surface terminations on the line shape of the spectra as well as the choice of the Raman experimental conditions are discussed. The line shape of the Raman spectrum of DND is also discussed in detail.