arXiv subjects

I. N. Terterov

Publications and source records attributed to I. N. Terterov.

2 recordsLinked to original sources

arXiv2018

Novel approach to Raman spectra of nanoparticles

In crystalline nanoparticles the Raman peak is downshifted with respect to the bulk material and has asymmetric broadening. These effects are straightly related to the finite size of nanoparticles, giving the perspective to use the Raman spectroscopy as the size probe. By combining the dynamical matrix method (DMM) and the bond polarization model (BPM), we develop a new (DMM-BPM) approach to the description of Raman spectra for random arrays of nanoparticles. The numerical variant of this approach is suitable for the description of small particles, whereas its simplier to implement analytical version allows to obtain the Raman spectra of arbitrary sized particles. Focusing on nanodiamond powders, the DMM-BPM theory is shown to fit the most recent experimental data much better than the commonly used phonon confinement model (PCM), especially for small enough nanoparticles.

cond-mat.mes-hall↗

arXiv2016

Molecular dynamics-based refinement of nanodiamond size measurements obtained with dynamic light scattering

The determination of particle size by dynamic light scattering uses the Stokes-Einstein relation, which can break down for nanoscale objects. Here we employ a molecular dynamics simulation of fully solvated 1-5 nm carbon nanoparticles for the refinement of the experimental data obtained for nanodiamonds in water by using dynamic light scattering. We performed molecular dynamics simulations in differently sized boxes and calculated nanoparticles diffusion coefficients using the velocity autocorrelation function and mean-square displacement. We found that the predictions of the Stokes-Einstein relation are accurate for nanoparticles larger than 3 nm while for smaller nanoparticles the diffusion coefficient should be corrected and different boundary conditions should be taken into account.

physics.flu-dyn↗