Raman Spectra and Bulk Modulus of Nanodiamond in a Size Interval of 2–5 nm

Abstract

Nanodiamond in a 2–5-nm size interval (which is typical for an appearance of quantum confinement effect) show Raman spectra composed of 3 bands at 1325, 1600, and 1500 cm−1 (at the 458-nm laser excitation) which shifts to 1630 cm−1 at the 257-nm laser excitation. Contrary to sp2-bonded carbon, relative intensities of the bands do not depend on the 458- and 257-nm excitation wavelengths, and a halfwidth and the intensity of the 1600 cm−1 band does not change visibly under pressure at least up to 50 GPa. Bulk modulus of the 2–5-nm nanodiamond determined from the high-pressure study is around 560 GPa. Studied 2–5-nm nanodiamond was purified from contamination layers and dispersed in Si or NaCl.

Pressure-Induced Transformation of Graphite and Diamond to Onions

“…In a case of covalently bonded solids, the bandgap growth means an increase in the chemical bond energy which means an increase in elastic moduli. Indeed, bulk modulus of the 2-5 nm nanodiamond is around 560 GPa, while bulk modulus of the 25 nm diamond being identical to bulk diamond (443 GPa) [16].…”

“…A Fritsch planetary mill with ceramic silicon nitride (Si 3 N 4 ) bowls and balls of 10 mm in diameter was used. Treatment in a planetary mill provides preparation of homogeneous nanocomposites without contamination by material of the balls [16]. The Raman spectra were recorded with a Renishaw inVia Raman microscope, excitation wavelength 532 nm (Renishaw plc, New Mills, Wotton-under-Edge, Gloucestershire, UK), and a TRIAX 552 (Jobin Yvon Inc., Edison, NJ, USA) spectrometer, equipped with a CCD Spec-10, 2KBUV Princeton Instruments 2048 × 512 detector and razor edge filters (excitation wavelength 257 nm).…”

Carbon at the nanoscale: Ultrastiffness and unambiguous definition of incompressibility

“…Nevertheless, the mechanical properties of single nanodiamonds -structural units of a nanocrystalline diamond -mainly remained unexplored until recently. However, the latest experimental evidence of nanodiamonds ultrastiffness [14,15] indicates that their mechanical properties also deserve detailed study.…”

“…Nevertheless, the mechanical properties of single nanodiamonds -structural units of a nanocrystalline diamond -mainly remained unexplored until recently. However, the latest experimental evidence of nanodiamonds ultrastiffness [14,15] indicates that their mechanical properties also deserve detailed study.Conventionally, mechanical stiffness is characterized by bulk modulus B0 as a measure of incompressibility. However, the calculation of elastic moduli for nanostructures can be puzzling due to the ambiguity of volume on the nanoscale.…”

Nanodiamenty: unikalne nanocząsteczki do zastosowania w biomedycynie i biotechnologii

“…Ze względu na korzystne właściwości magneto-optyczne uwarunkowane krystaliczną strukturą, NDs mogą być alternatywą dla wcześniej wymienionych nanocząsteczek [5]. Wysoki współczynnik załamania światła umożliwia uzyskanie ostrego piku w widmie spektroskopii fourierowskiej w podczerwieni oraz ramanowskiej spektroskopii [50,87]. Ramanowskie mapowanie wykorzystano w praktyce do lokalizacji NDs sprzę-żonych z hormonem wzrostu w celu określenia jego interakcji z receptorami błonowymi komórek raka płuc [88].…”