The size of interstellar nanodiamonds revealed by infrared spectra of CH on synthetic diamond nanocrystal surfaces

Abstract

Infrared spectra of CH stretches have been investigated on the surfaces of synthetic diamond crystallites (5, 100, and 700 nm in diameter) to provide insights into the mid-infrared emission bands of stardusts in interstellar media. While the spectrum of 5-nm diamonds fails to display the distinct 2835 cm−1 (or 3.53 μm) band, a remarkably good match of the absorption bands of larger diamond grains with the emission observed for the stars Elias 1 and HD 97048 is obtained. Suggested by this study, the nanodiamonds that can display such characteristic emission bands at 3.53 μm in these two interstellar systems have a size significantly larger than 5 nm.

Young's modulus, fracture strength, and Poisson's ratio of nanocrystalline diamond films

“…45 The absence of welldefined facets on the grain surfaces for smaller grain sizes inhibits the observation of the C-H vibrations. [45][46][47] In contrast, an increasing hydrogen concentration is usually observed in diamond films for decreasing grain size due to higher volume fraction of grain boundaries. 2, 45,48,49 A decrease in the elastic modulus has been reported for increasing amount of hydrogen present in (ultra-) nanocrystalline diamond films.…”

Functionalized Nanodiamonds: Triamantane and [121]Tetramantane

“…Nanodiamonds, which are nanometer-sized single-molecule hydrocarbons, close the gap between chemistry, physics, and the material sciences in terms of their size and properties . Indeed, the size of microcrystalline hydrogen-terminated nanodiamonds approaches 2 nm (Figure ), , which is very close to the dimensions of medium-sized diamondoid hydrocarbons (1−2 nm). The physics community uses the term “nanodiamonds” for the constituents of diverse systems including interstellar dusts and meteorites, carbonaceous residues of detonations, and diamond-like films .…”

Nanodiamonds: Synthesis and Application in Sensing, Catalysis, and the Possible Connection with Some Processes Occurring in Space

“…Finally, a comprehensive list of papers on regarding the liquid state of carbon in stellar and planetary interiors, and possible nanodiamond-related origin of ERE can be found in References [135][136][137][138][139][140][141][142][143][144][145].…”