Characterization of Interface Layers of a Solid Solution Formed During the Growth of a Carbide Layer on Silicon From Hydrogen Containing Compounds

Fabrication of Silica Optical Fibers: Optimal Control Problem Solution

“…If the output of the object can be considered small deviations of ∆Θ(t, z) from some temperature Θ * (t, z) = Θ * , while assuming that Θ(t, z) = Θ * + ∆Θ(t, z), then with fairly smooth dependencies ρ(Θ), C p (Θ), λ(Θ), Equation ( 8) can be linearized in the vicinity of temperature Θ(t, z)| z=0 = Θ 1 (t), ∂Θ(t,z) ∂z z=L = Θ 2 (t) by expanding nonlinear dependencies into a Taylor series. We use this technique in Equation (8), which is a one-dimensional second-order differential equation with a nonlinear operator calculated as follows:…”

“…The advantage of these methods is the possibility of obtaining pure or doped silicon dioxide containing impurities of the "coloring" metals (Fe, Cu, Mn, Co, Cr, Ni) at a level of <10 −7 wt%, which virtually eliminates losses associated with the absorption of light in the range of 0.63 to 1.55 µm [6]. The production of such pure oxides is considered because of the use of especially pure starting halides [7] (in which the concentration of impurities of these metals is at a level of 10 −7 -10 −8 wt%, and hydrogen-containing compounds at a level of 10 −4 -10 −7 wt%) [8]. Additional purification occurs during their evaporation, since the "coloring" metal halides have a significantly higher boiling point than the above-listed halides and, accordingly, lower saturated vapor pressure at the working temperature of the bubblers.…”