A.T. Dideikin

Defects and impurities in nanodiamonds: EPR, NMR and TEM study

Abstract EPR, 13 C NMR and TEM study of ultradisperse diamond (UDD) samples is reported. The compounds show a high concentration of paramagnetic centers (up to 10 20 spin/g), which are due to structural defects (dangling C–C bonds) on the diamond cluster surface. The anomalous reduction in the spin–lattice relaxation time of 13 C (from several hours in natural diamond to ∼150xa0ms in UDD clusters) is attributed to the interaction between the unpaired electrons of the paramagnetic centers and nuclear spins. 13 C NMR line-width reflects the fact that the structure of the UDD surface is distorted in comparison to the ‘bulk’ diamond structure.

Thermoelectric Effect in Field Electron Emission from Nanocarbon

We suggest a model of field emission from nanocarbon materials, which accounts for the electron drag by ballistic phonons through the temperature gradient region of the emission center. The model does not require additional assumptions of a special energy structure of the emission center. The numerical calculations made within this model agree well with available experimental data.

CHAPTER 2:Detonation Nanodiamonds: Synthesis, Properties and Applications

This chapter addresses present-day views on the synthesis, properties and applications of nanodiamonds fabricated by the detonation of strong explosives, the so-called detonation nanodiamonds (DND). The chapter focuses primarily on the results of DND studies, which have been reliably established and universally accepted, while stressing at the same time the points that, in our opinion, still remain controversial. The main content relates to the features of technology for DNDs, the structure of single DND particles and their suspension, as well as the various applications of DNDs.

Effect of chemical treatment on the structure of ultradisperse diamond and onion-like carbon

The effect of extraction conditions and a post-treatment in hydrogen atmosphere at high temperature (HTT) on the surface structure and purity of ultradisperse diamond (UDD) have been studied by means of X-ray diffraction, small angle X-ray scattering, HRTEM and EPR.

Chemical composition of surface and structure of defects in diamond single crystals produced from detonation nanodiamonds

The possibility of growing bulk single crystals from detonation nanodiamond (DND) particles by oriented attachment in the presence of alcohols or/and hydrocarbons was predicted and experimentally demonstrated by our group in previous works [1–3]. It is assumed that diamond single crystals of size between 500 nm and 15 mcm are formed directly from 4 – 5 nm sized diamond nanoparticles under conditions of high pressure and high temperature (HPHT)(P ≈ 7 GPa, T ≈ 1300 – 1700 ◦C). One of the most promising applications of synthesized diamond microcrystals is related to the formation of luminescent impurity centers inside diamond lattice from their own system of defects originating during crystal growth. The distinction of composition and structure of lattices defects in sintered microcrystals and initial DND particles was found for the first time by ESR [4, 5]. The goal of present work is studying transformation of composition and structure of defects of DND resulting from forming microcrystals by HPHT sintering, as well as estimating the possibility of obtaining of the luminescense centers (nitrogen-vacancy) in microcrystals obtained by sintering of DND particles.

Reduction of the graphene oxide films by soft UV irradiation

We have studied the UV reduction process of thin graphene oxide films, deposited on silicon substrate from ethanol suspension. Chemical structure of obtained material was analyzed by XPS method. TEM images showed holes formation during reduction process, that are connected into network. Films with observed structure have great variety of possible future applications, such as gas-sensors and different organic/nonorganic nanocomposites.