The formation of zircon from amorphous ZrO2 · SiO2 powders
The formation of zircon from amorphous ZrO2 · SiO2 powders
复制标题
无定形 ZrO2·SiO2 粉末形成锆石
DOI：
--
复制
发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Francisco Guitián
中科院分区：
文献类型：
--
作者：
P. Tartaj;Carlos J. Serna;J. Moya;J. Requena;Manuel Ocaña;S. Aza;Francisco Guitián
本文研究了影响非晶态ZrO_2·SiO_2粉末中锆英石形成机理的各种因素。结果表明，锆英石是由四方氧化锆与二氧化硅（无定形和方石英）固相反应生成的。先前提出的Hedvall效应与无定形二氧化硅结晶成方石英没有发挥任何作用，在这个反应。在起始非晶粉末中的高程度的Si-Zr混合不影响锆石形成的机理，但由于在锆石形成之前分离的氧化锆和二氧化硅颗粒的小颗粒尺寸而加快了反应速率。有人还发现，形成反应是由来自醇盐前体，这可能是在煅烧后保留在晶界，作为扩散屏障的碳质物种的存在下，延缓。这些因素可以解释以前报道的锆石形成温度的差异。
The different factors affecting the mechanism of zircon formation from amorphous ZrO2 · SiO2 powders have been studied. It was shown that zircon was formed by solid state reaction between tetragonal zirconia and silica (amorphous and cristobalite). The previously suggested Hedvall effect associated with the crystallization of amorphous silica into cristobalite did not play any role in this reaction. A high degree of Si-Zr mixing in the starting amorphous powders did not affect the mechanism of zircon formation, but speeded up the reaction rate due to the small particle size of the zirconia and silica particles segregated previously to zircon formation. It was also found that the formation reaction was retarded by the presence of carbonaceous species coming from the alkoxide precursors, which were probably retained at grain boundaries after calcination, acting as a diffusion barrier. These factors can explain the observed differences in the temperatures of zircon formation previously reported.