The products of the interaction between silicon carbide (SiC) and silica at the temperature range of 1400 to 2000$^{o}$ C were investigated by X-ray powder diffraction methods and Auger electron spectroscopy. The starting powder was prepared by zol-gel technology [1] and one consisted of fault $\beta$-SiC and amorphous SiO$_{2}$. The regularity of the cubic silicon carbide's peaks shift shows the existence of the deformation stacking faults [2] in his structure. The presence of the additional diffraction maxima (which has indexes (100) if $\beta$-SiC structure is described in hexagonal axes) in his spectra is likely due to unequiprobable distribution of the close packed layers.
In contrast to existent knowledge it is shown that the products of the interaction between SiC and SiO$_{2}$ at 1750$^{o}$ C are carbides having composition approximately Si$_{2}$C and not free silicon [3]. One of them is amorphous and the other ($\gamma$ Si$_{5}$C$_{3}$) has crystal state (cubic structure like FeSi type with lattice parameter a = 4.523 \AA). It is established that due to secondary heat-treatment the amorphous phase breaks down into $\beta$-SiC and Si at the lowest temperature (1400$^{o}$C). The more stable $\gamma$-carbide transforms to unknown $\delta$-carbide in the temperature interval 1500-1700$^{o}$C. One cell can belongs to either hexagonal (a = 6.77 Å, c = 4.77 Å) or orthorhombic (in one of possible cases a = 2.93Å, b = 3.39Å, c = 4.77Å) syngony.
On treatment at 2000$^{o}$C the samples which have carbides Si$_{2}$C the formation of silicon is observed. Thus it indicates that in some conditions such carbides are intermediate stage in reduction of SiC by SiO$_{2}$ to free silicon. On the base of the experimental data the scheme of the reactions between SiC and SiO$_{2}$ is suggested.
1.Schwetz K.A., Lipp A.: Herstellung und Eigenschaften ultrafeiner
$\beta$-SiC - Sinterpulver Radex-Rundschau. 1978. N2. S.
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2.Warren B.E.: X-ray diffraction. Addison-Wesley Publishing
Company, 1969. P.275-298.
3.B.V.Khaenko, E.V.Prilutsky, A.A.Mikhailik,
M.V.Karpets, A.V.Krainikov: Inorganic Materials. Vol.31. N3.(1995) P.327-332.