V. N. Fokin

Deuterofullerene C60D24 studied by XRD, IR and XPS

Abstract The deuterofullerene C60D24 was prepared from the solid C60 and was characterised by means of XRD, IR and XPS. The C60D24 was found to be a polycrystalline powder with a FCC lattice and a=14.55 A. Deuterium thermal desorption from C60D24 leads to a reversible formation of fullerene. However, the distances between the C60 molecules become significantly longer compared to the initial fullerite.

Hydride and ammonia dispersion of metals

Chemical (hydride and ammonia) dispergation of Group II–V metals induced by hydrogen and ammonia in the temperature range of 100–500°C at a pressure of 0.5–2.0 MPa was studied. The phase transitions in the M-H2 and M-NH3 systems were investigated and conditions for metal hydride and nitride formation as highly dispersed powders were identified. The characteristic features of metal dispergation under the action of hydrogen and ammonia and the degrees of dispersity of the obtained powders were compared.

On the thermal decomposition of the C60D19 deuterium fullerite

The gas-phase products of thermal decomposition of the C60D19 deuterium fullerite are studied by mass spectrometry. It is found that, in addition to D2 molecules, the gas phase over the deuterium fullerite sample heated to a temperature of 773 K contains CD4 methane and C6D6 benzene molecules. The deuterocarbon molecules are revealed in the gas phase even at 673 K.

Hydrogenation of fullerites in the presence of intermetallic compounds or metals

Fullerene hydrides containing 24–26 H atoms per fullerene molecule were obtained by hydrogenation of solid-phase mixtures of fullerenes with either intermetallic compounds LaNi5, LaNi4.65Mn0.35, CeCo3 or V and Pd metals with gaseous hydrogen at 1.0–2.5 MPa and 573–673 K. These fullerene hydrides decompose at 800 K with evolution of H2. Upon subsequent heating to 1000 K, vanadium reacts with fullerene to yield a cubic phase of vanadium carbide. The intermetallic compounds react with fullerene with the formation of a metallic phase of the 3d-metal and destruction of fullerene. Palladium does not react with fullerene.

Chemical interaction between TiFe and ammonia

We have studied chemical interaction between the intermetallic compound TiFe and ammonia at temperatures from 150 to 500°C in the presence of NH4Cl as an activator of the process. We have derived schemes of the reactions involved and have shown that the use of ammonia for hydriding/nitriding enables the preparation of fine powders of TiFe and its hydride.

Synthesis and properties of crystalline fullerene hydrides

The interaction of crystalline fullerence C60 with highly pure hydrogen, which was evolved from hydrides of intermetallic compounds of rear-earth metals and nickel, was studied. Crystalline fullerene hydrides containing from 10 to 30 hydrogen atoms per fullerene molecule were synthesized (1.0–2.5 MPa and 300–673 K). Crystalline hydrides release hydrogen at 800 K with retention of the structure of the fullerene molecule.

Hydrogenation of the intermetallic compound Zr2Ni

We have determined conditions for the preparation of hydride phases with the composition Zr2NiH∼5 by reacting the intermetallic compound Zr2Ni with hydrogen or ammonia and identified the products of the reaction between the intermetallic compound and ammonia in the temperature range 150–500°C in the presence of NH4Cl as an activator. The results demonstrate that the use of ammonia at 500°C leads to decomposition of the intermetallic compound and formation of zirconium hydride, zirconium nitride, and metallic nickel.

Hydriding of Mg2Ni in ammonia

The chemical interaction between the intermetallic compound Mg2Ni and ammonia in the presence of NH4Cl as an activator is investigated at temperatures from 100 to 450 °C, and the reaction scheme is presented. The results demonstrate that the use of ammonia for hydriding/nitriding the intermetallic compound makes it possible to prepare various magnesium compounds (Mg2NiH4, Mg3N2, and Mg (NH2)2) in a highly dispersed state.

Hydriding of intermetallic compound Ti2Ni

Conditions of formation of the Ti2NiH3.3 hydride phase in the reaction of the Ti2Ni intermetallic compound with ammonia and hydrogen have been determined. The products of the reaction of the intermetallide with ammonia in the presence of the NH4Cl activator in the temperature range 100–500°C have been identified. It has been shown that the use of ammonia at temperatures >400°C leads to the formation of titanium nitride and nickel.

Reaction of the intermetallide ZrV2 with ammonia

The reaction of the intermetallic compound ZrV2 with ammonia within a temperature range of 150–500°C in the presence of NH4Cl as an activator of the process was studied. Depending on the reaction temperature, intermetallide hydrides and compositions of metal hydrides and nitrides or metal nitrides were obtained in the form of finely dispersed powders with particle sizes of less than 1.0 μm.