Найдено научных статей и публикаций: 2, для научной тематики: SiC
1.
E. N. Kalabukhova, S. N. Lukin, D. V. Savchenko, B. D. Shanina, A. V. Vasin, V. S. Lysenko, A. N. Nazarov, A. V. Rusavsky, J. Hoentsch, Y. Koshka
- Physical Review B , 2010
Three paramagnetic defects were revealed in amorphous hydrogenated carbon-rich silicon-carbon alloy films a-Si0.3C0.7:H. Two of them were attributed to silicon Si dangling bonds Si DBs and carbon-related defects CRDs. The third defect, based on its g-value and linewidth, was tentatively attrib...
Three paramagnetic defects were revealed in amorphous hydrogenated carbon-rich silicon-carbon alloy films a-Si0.3C0.7:H. Two of them were attributed to silicon Si dangling bonds Si DBs and carbon-related defects CRDs. The third defect, based on its g-value and linewidth, was tentatively attributed to a bulk Si DB defect
bonded with nitrogen atoms in Si-N2Si configuration. The effect of thermal vacuum annealing on the properties of the a-Si0.3C0.7 :H films was studied in the temperature range of Tann=400–950 °C. A strong increase in CRD concentration was observed in high temperature annealed a-Si0.3C0.7 :H films, which was explained by hydrogen effusion process occurred at Tann above 400 °C. The increase in the concentration of the CRDs is accompanied by the exchange narrowing of its electron paramagnetic resonance EPR linewidth due to the
formation of carbon clusters having ferromagnetic ordering. The temperature dependent g-factor anisotropies observed at Q-band and D-band frequencies for the CRD signal in the samples annealed at high temperature 950 °C were explained by the presence of graphitelike sp2-coordinated carbon clusters and demagnetization
field shape-dependent anisotropy term. The demagnetizing field Bdem=−4Ms, where Ms is the sample magnetization, was found to be equal to 0.44 mT at 37 GHz and 1.1 mT at 140 GHz. Analysis of the temperature dependences of the integral intensities of the SiDB and CRD EPR signals has shown that they do not obey the Curie-Weiss law, and their spin systems exhibit superparamagnetic and ferromagnetic properties, respectively.
2.
Savchenko D., Kassiba A.., Ogurtsov N., Errien N., Makoswka-Janusik M., Pud A., Kodjikian S., Oueriagli A.
- IEEE Conference Proceeding: ICTON Mediterranean Winter Conference (Angers, France, December 10-12), 2009. ICTON-MW 2009. 3rd , 2010
Electron paramagnetic resonance (EPR) investigations were carried out on hybrid Core-Shell nanomaterials
associating silicon carbide nanoparticles and conducting polyaniline. The performed experiments compare the
paramagnetic centres, the electronic transport features and the interface effects in ...
Electron paramagnetic resonance (EPR) investigations were carried out on hybrid Core-Shell nanomaterials
associating silicon carbide nanoparticles and conducting polyaniline. The performed experiments compare the
paramagnetic centres, the electronic transport features and the interface effects in two classes of materials, bare
polymers and core-shell nanocomposites. By EPR, large doping rates were demonstrated in the bare doped
polymers through important saturation phenomena which alter significantly the EPR spectrum features.
Furthermore, memory effects were involved in the bare doped polymer with regard to the EPR spectrum features
depending on the conditions of its thermal treatments. In the hybrid core-shell nanocomposites nor such
saturation and nor memory effects were found on the EPR signals even if similar paramagnetic centres exist in
both classes of samples. These behaviors were discussed taking into account the thermal stability and the doping
efficiency in the considered classes of materials. Optimal doping levels were then realized and their effects on
the polymers and the nanocomposites were clarified by using EPR and DRS (dielectric relaxation spectroscopy)
measurements. Also, it is demonstrated that the charge carriers consist in polarons in the nanocomposites while
bipolarons contributions dominate the electrical conductivity in the bare doped polymers