Amorphous silica containers for germanium ultrapurification by zone refining

作者：Podkopaev O I^*; Shimanskii A F; Kulakovskaya T V; Gorodishcheva A N; Golubovskaya N O

来源：Inorganic Materials, 2016, 52(11): 1091-1095.

DOI：10.1134/S0020168516100125

• melt
• container materials
• amorphous silica
• fused silica
• ceramic
• contact angle
• work of adhesion

We have studied the wetting behavior of molten germanium on silica ceramics and amorphous silica coatings in vacuum at a pressure of 1 Pa and a temperature of 1273 K. The results demonstrate that the wetting of rough surfaces of ceramic samples and coatings by liquid Ge is significantly poorer than that of the smooth surface of quartz glass. The contact angle of polished glass is similar to 100A degrees, and that of the ceramics and coatings increases from 112A degrees to 137A degrees as the total impurity content of the material decreases from 0.120 to 1 x 10(-3) wt %. Using experimental contact angle data, we calculated the work of adhesion of molten Ge to the materials studied. Its value for the surface of the ceramics and coatings decreases from 0.45 to 0.20 J/m(2) with decreasing impurity content, whereas the work of adhesion to a smooth glass surface is 0.55 J/m(2). We have fabricated fused silica test containers coated with high-purity amorphous silica. Using horizontal zone refining, we obtained germanium samples with a carrier concentration difference on the order of 10(11) cm(-3).

• 出版日期2016-11