E. A. Petrakovskaya

The research of powder fullerene and ultra-dispersed diamond composites with metal and oxide nanoparticles

Magnetic properties of new nanophase materials based on oxide and metal particles of d transition metals included in the powder fullerite C60 and detonative ultradispersed diamonds (UDD) are investigated. The materials are obtained by an original method of catalytic combustion reaction.

EPR investigation of local paramagnetic centers in perovskite-like crystals

In ScF3 single crystals (pure and doped) as well as in Rb2KScF6 and Rb2KDyF6 crystals with a perovskite-like structure, point nanodefects (vacancy in place of trivalent cations) have been found and studied. Electron paramagnetic resonance has been used to investigate local paramagnetic centers that are not detected using X-ray diffraction. The angular dependence of the spectra indicates a local distortion of the cubic symmetry of the crystals. An additional hyperfine structure in the observed spectra is due to the delocalization of electrons over six F− ions forming the first coordination polyhedron around the vacancy. The crystals studied are characterized by a high electron mobility and a high electron velocity, which depends on the impurity. The high mobility of electrons of the cation center can be indirectly responsible for the structural phase transition occurring in the ScF3 crystal under uniaxial pressure.

Synthesis and study of manganese-containing endohedral fullerenes

Fullerenes containing manganese and iron atoms are synthesized in a high-frequency carbonhelium plasma at atmospheric pressure. The electron paramagnetic resonance (EPR) spectrum of the synthesized compound contains not only lines attributed to iron atoms but also the lines of a manganese ion pair with an additional hyperfine structure. The latter lines are assigned to the endohedral complex Mn2@Cn (n > 70). The possible existence of these structures is evaluated from quantum-chemical calculations of the optimum geometry of the endothedral fullerene Mn2@C84 with C2v symmetry. It is found that the manganese atoms are spaced ∼2.72 Å apart at the center of the molecule.

Magnetite Nanoparticles in Fullerite C60 Powder

Data are presented on the resonance and magnetic properties of Fe–fullerene nanomaterials prepared by heating a mixture of C60 fullerene and iron(III) acetylacetonate. The starting-mixture composition is shown to have a significant effect on the particle size and properties of the resulting magnetite and the magnetic properties of the material. The influence of chemical treatment on the properties of the material is analyzed.

A study of the synthesis products of fullerenes with nickel and cobalt

Qualitative analysis of the products of plasmochemical synthesis of fullerenes with metallic nickel and cobalt has been carried out using electron paramagnetic resonance (EPR) and electron microscopy. These studies show that the synthesis products are mainly fullerenes, metallic nanoparticles coated with an insulating layer, and isolated atomic clusters.

Superparamagnetism of magnetite particles in C60 fullerite powder

A new magnetic material, C60 fullerite powder doped by magnetite (Fe3O4) nanoparticles, is obtained by heating a mixture of fullerite and iron(III) acetylacetonate. It is shown that the material offers superparamagnetic properties. Surface bonding between the nanoparticles and the fullerite is established.

Thermal reactions of fullerene C60 with iron(III) acetylacetonate

Thermal reaction of solid mixtures of fullerene C60 with iron(III) acetylacetonate proceeds in the combustion mode; the composition and characteristics of the reaction products are governed by the Fe : C60 ratio in the initial mixture. The magnetization of iron-fullerene complexes was measured.