Reactive force-field molecular dynamic models of iron/oxide/carbon nanocomposites designed for magnetic hyperthermia

Abstract

The study is devoted to nanoparticles with an iron core and an oxide shell structure, which are enclosed by an additional carbon layer. Such particles are promising for magnetic hyperthermia due to their stability in an AC magnetic field and the tunability of the magnetic properties by varying of the thickness of the oxide shell. To determine the correspondence between the atomic structure of synthesized nanoparticles to expectations, the core-shell structure with an additional carbon coating is modeled on the basis of classical molecular dynamics with a reactive force field that allows chemical bonds to form and break. The results of the molecular dynamics simulation are compared with the pair radial functions obtained from the analysis of the extended fine structure of X-ray absorption spectra near the Fe K edge. The resulting model of the cluster Fe 1564 O 409 demonstrates the stability of its atomic structure (at least for 4 ps) at room temperature. The results can be used to study the efficiency for magnetic hyperthermia and the biological effect of the obtained nanocomposites.