Analysis of the reaction at the interface between Si melt and Ba-doped silica glass

Surface Basic Site Effect on Boron-Promoted Platinum Catalysts for Dry Reforming of Methane

“…Based on XRD studies summarized in Figure , the amorphous boron-doped silica had morphed into the cristobalite morphology at high temperatures, which would drastically change the surface area of the catalyst. The transformation of amorphous silica to cristobalite has been extensively investigated at low pressures and high temperatures. , However, when silica is doped with a compound, which may act as a crystallization nucleation site, the transformation to cristobalite can occur at ambient pressure and high temperatures, as observed in Figure …”

“…53,54 However, when silica is doped with a compound, which may act as a crystallization nucleation site, the transformation to cristobalite can occur at ambient pressure and high temperatures, as observed in Figure 7. 55 Cristobalite is known to have a significantly lower surface area than amorphous silica, which could be a factor for active site accessibility. The BET surface area was then determined, and the results are described in Table 3.…”

Reactions between Si melt and various ceramics

“…Local cristobalite SiO 2 formation can easily result in a crack formation at the surface of Si. Huang et al [9,10] found that when the Ba concentration in silica glass was >30 ppm, the cristobalite SiO 2 changes to a dense, smooth, and continuous layer, which results in the reduction of the precipitation of Si inclusions and defects. The formation mechanism of the Ba-doped cristobalite layer is considered to be a heterogeneous nucleation caused by Ba additives.…”

Quality of n-Type Czochralski Silicon Crystals for Solar Cells Grown from the Melt in Liquinert Crucibles

“…8 It has been known that the Ba-doped in silica glass accelerates crystobalite (polycrystalline structure of SiO 2 ) formation by phase transition directly from the silica glass, effectively suppressing so-called brownish rings at the inner surface and increasing the yield of monocrystalline silicon growth. 9,10 Applying the Ba-doped silica crucible to multicrystalline silicon growth, Hsieh et al 11 found that the problem of solidified silicon sticking to the crucible surface could be resolved. However, they reported that the improvement of the lifetime was not observed probably because the doped layer was too thin.…”