Tetrachlorosilane Consumption in Radio Frequency Glow Discharge

Time-resolved mass spectrometry was used for analysis of the plasma reactions in radio frequency (RF) SiCl ₄ and SiCl ₄ –O ₂ discharges as functions of starting partial pressure and electrical power. Molecular concentrations of the reactants and products from SiCl ₄ alone and with O ₂ were obtained from the mass spectra and used for plotting the kinetic curves. The SiCl ₄ and O ₂ consumption rates were calculated from the kinetic curves and compared with results of theoretical simulation of the reaction. Direct electron impact decomposition was found to be the main pathway for pure SiCl ₄ conversion. On the contrary, the consumption of SiCl ₄ in the SiCl ₄ +O ₂ mixtures was largely chemical. The experimental macrokinetics are in agreement with a model in which oxidation is caused by the atomic oxygen.     

Neutron activation analysis of refractory compounds

Instrumental neutron activation techniques for the determination of 26–36 impurities in MoSi₂, WSi₂, TiB₂, NbB₂, TiC, NbC and SiC with detection limit of 0.1–0.000001 ppm in the range of contents of 100–0.001 ppm have been developed. The determination of this large number of elements was achieved with using complex conditions of irradiation, including varying neutron energy and choosing optimal time parameters. The contents of short-lived radionuclides also have been determined. Self-shielding and disturbance of neutron flux, absorption of -rays were taken into account both with the help of literature data and preliminarily obtained experimental results.     

Einstein relation for quantum systems

The Einstein relation between the diffusion constantD and the mobilityu is discussed for various quantum systems, proceeding from the analysis of the general thermodynamic relation. Comparison between the kinematic and the thermodynamic derivation reveals the possibility to use the Einstein relation in investigations of the particle energy distribution in nonequilibrium conditions.     

Stability of longitudinally compressed cylindrical shells beyond the elastic limit with edge effects taken into account

International Applied Mechanics -     

Coherent magnetic breakdown

A theory of Coherent Magnetic Breakdown (CMB) is presented here. CMB is observed at low temperatures in pure metallic samples. Different phenomena are being considered in conditions of MB: high frequency phenomena, sound absorption etc.