Valery A. Davydov

Pressure-induced dimerization of fullerene C60: a kinetic study

Abstract The kinetics of pressure-induced dimerization of fullerite C60 at 1.5 GPa in the 373–473 K temperature interval was studied by X-ray diffraction, infrared and Raman spectroscopy. Kinetic curves of the dimerization reaction in the fcc and sc phases of C60 were obtained by monitoring the dimeric (C60)2 IR line at 796 cm−1. The value of the dimerization activation energy was determined to be E a ( dim ) =134±6 kJ mol −1 , assuming the second order irreversible reaction. The peculiarities of the dimerization processes in the fcc and sc phases of C60 fullerite are also discussed.

Spectroscopic properties of individual pressure-polymerized phases of C60

Abstract The Raman and IR spectra of pure polymerized phases of C 60 obtained at high pressure and temperature were investigated. Our data showed that some previous spectra were obtained from a mixture of different polymeric states. Determination of the characteristic bands of dimer, chain and layer polymers permit the use of the IR and Raman spectra in the molecular fractional analysis of different polymerized states of C 60 .

Solid state synthesis of carbon-encapsulated iron carbide nanoparticles and their interaction with living cells

Superparamagnetic carbon-encapsulated iron carbide nanoparticles (NPs), Fe7C3@C, with unique properties, were produced from pure ferrocene by high pressure-high temperature synthesis. These NPs combine the merits of nanodiamonds and SPIONs but lack their shortcomings which limit their use for biomedical applications. Investigation of these NPs by X-ray diffraction, electron microscopy techniques, X-ray spectroscopic and magnetic measurement methods has demonstrated that this method of synthesis yields NPs with perfectly controllable physical properties. Using magnetic and subsequent fractional separation of magnetic NPs from residual carbon, the aqueous suspensions of Fe7C3@C NPs with an average particle size of ∼25 nm were prepared. The suspensions were used for in vitro studies of the interaction of Fe7C3@C NPs with cultured mammalian cells. The dynamics of interaction of the living cells with Fe7C3@C was studied by optical microscopy using time-lapse video recording and also by transmission electron microscopy. Using novel highly sensitive cytotoxicity tests based on the cell proliferation assay and long-term live cell observations it was shown that the internalization of Fe7C3@C NPs has no cytotoxic effect on cultured cells and does not interfere with the process of their mitotic division, a fundamental property that ensures the existence of living organisms. The influence of NPs on the proliferative activity of cultured cells was not detected as well. These results indicate that the carbon capsules of Fe7C3@C NPs are air-tight which could offer great opportunities for future use of these superparamagnetic NPs in biology and medicine.

All-optical nanoscale thermometry with silicon-vacancy centers in diamond

We demonstrate an all-optical thermometer based on an ensemble of silicon-vacancy centers (SiVs) in diamond by utilizing a temperature dependent shift of the SiV optical zero-phonon line transition frequency,

Magnetocontrollability of Fe7C3@C superparamagnetic nanoparticles in living cells.

\Delta\lambda/\Delta T= 6.8\,\mathrm{GHz/K}

Magnet-induced behavior of Iron Carbide (Fe7C3@C) Nanoparticles in the Cytoplasm of Living Cells

. Using SiVs in bulk diamond, we achieve

Ab Initio and DFT-Based Assignment of the Vibrational Spectra of Polymerized Fullerenes

70\,\mathrm{mK}

New superparamagnetic fluorescent Fe@C-C5ON2H10-Alexa Fluor 647 nanoparticles for biological applications

precision at room temperature with a sensitivity of

Comparative EPR Study of Monomer and Polymerized Phases of C60

360\,\mathrm{mK/\sqrt{Hz}}

Raman Study of Hydrogenated and Fluorinated Single-walled Carbon Nanotubes

. Finally, we use SiVs in