Search

Time-of-flight secondary ion mass spectra measured for different carbon allotropes under Bi3+ cluster ion bombardment were acquired. Ion yield of homogeneous (Cn)- and heterogeneous metal-carbon (CsCn)- secondary cluster ions was examined. Qualitative explanation of the regularities was given based on the concept of nonlinear atomic collision cascades. It was suggested that that the features of secondary cluster yield can be used for determination of hybridization state of the target material. Unlike most other techniques, secondary ion mass spectrometry is capable of the sputter depth profiling of the hybridization state.

The method of ion-plasma pulse-arc sputtering of graphite in a methane atmosphere has been employed to produce carbon films with different rate of sp1-bonds having a significant impact on the electrical conductivity of those films. Raman spectroscopy showed that the line near 2040 cm−1, corresponding to the oscillation of long carbon chains with sp1-hybridization, became more prominent with increase of methane concentration in the vacuum deposition chamber. The obtained spectra revealed multiphonon replicas of the 2040 cm−1 line that is evidently associated with the presence of defects in carbon chains.

We present a modified approach to the synthesis of sp-based films. This technique includes two stages: the dehydrohalogenation of polyvinylidene chloride powder and its subsequent sputtering. The synthesized films were characterized by Raman spectroscopy, infrared spectroscopy, X-ray photoelectron spectroscopy, and X-ray excited Auger electron spectroscopy. The films were shown to consist of sp-hybridized carbon chains and nanocrystalline graphite. Sp-carbon evaporation and sp-hybridized clusters sputtering mechanisms leading to sp-clusters transfer from an sp-rich target to the growing film surface were discussed.

Amorphous carbon structures containing silver nanoparticle inclusions were synthesized by ion-assisted pulse-plasma deposition. Coatings were investigated by transmission electron microscopy, electron diffraction, electron energy loss spectroscopy, Raman spectroscopy and ultraviolet-visible (UV-Vis) absorption spectroscopy. Ion assistance energy variation was found to affect silver nanoparticles shape, carbon matrix composition and clustering. UV-Vis absorption spectra dependence on the structural changes was discussed.

We present an investigation of carbon-silver composite thin films obtained by ion-assisted pulse-plasma sputtering of graphite cathode with silver inclusions. Transmission electron microscopy, X-ray photoelectron spectroscopy were used to analyze the films structural properties. It was shown that the films consist of amorphous carbon matrix and silver nanoclusters. The increase of assisting ions energy from 0 eV to 300 eV resulted in decrease of silver nanoclusters average size and their number density increase. Variation of the films extinction spectra with deposition parameters change was studied.

The influence of ion assistance on electrical and structural properties of a-C:N films was studied by electron energy loss spectroscopy, X-ray photoelectron spectroscopy, transmission electron spectroscopy, electron diffraction and four-probe conductivity measurements. It was shown that ion assistance in nitrogen atmosphere led to the significant decrease in electrical resistivity of the films. This effect was explained by the formation of nanographite clusters induced by nitrogen. The lowest value of room-temperature electrical resistivity of the films was observed at 400 eV ion assistance energy. This minimum was found to be defined by two competing processes affecting films conductivity in opposite ways: with the assistance energy increase, the fraction of sp2-hybridized carbon atoms raised, but the nanocluster size decreased.