Structure and Luminescence Properties of Nanonodiamonds Produced from Adamantane

Abstract

Nano‐ and micro‐diamonds synthesized from organic compounds at high pressure are a new class of diamond materials, whose physical and chemical properties are not yet studied. In this paper, the structural and luminescence features of such diamonds on an example of a sample synthesized from adamantane at a pressure of 8–9 GPa and a temperature of 1700 K is investigated. In Raman spectra of the sample, lines corresponding to vibrational energies of CHx bonds are found, that reveals a termination of carbon bonds on a diamond surface by hydrogen atoms and explains hydrophobic properties of this material. It is shown, that the hydrophobic properties of nanodiamonds can be replaced by hydrophilic ones by heating them in air up to 700 °C. In photoluminescence spectra of the as‐grown sample, a number of narrow lines are detected in the range of 490–650 nm. Their intensity is insignificant in comparison with the Raman line of diamond and fluctuates in time independently for each of the lines. It is assumed that these lines are associated with a small amount of oxidized graphene clusters on a surface of the diamond nanoparticles.