Crystallisation kinetics and structural stability of transparent CaF2 glass ceramics: Dependence of light transmittance on the amount of CaF2 added
Crystallisation kinetics and structural stability of transparent CaF2 glass ceramics: Dependence of light transmittance on the amount of CaF2 added
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DOI：
10.1016/j.ceramint.2020.03.072
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发表时间：
2020-07
影响因子：
5.2
通讯作者：
Xiwang Miao;Xiangtao Huo;Lei Liu;Shujie Tang;Min Guo;F. Cheng;Mei Zhang
中科院分区：
文献类型：
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作者：
Xiwang Miao;Xiangtao Huo;Lei Liu;Shujie Tang;Min Guo;F. Cheng;Mei Zhang
研究了caf2添加量（15.4、20.4、27.4和35.4 wt%）对含caf2纳米晶透明玻璃陶瓷（TGCs）结晶能力和制备的影响。结果发现，含有15.4、20.4和35.4 wt% caf2的样品结晶为多晶相，使TGCs不透明。只有当CaF2added的数量增加到27.4 wt %, tgc只有CaF2nanocrystals可以成功地由热处理在630和730°C 2 h。样品的结晶活化能为27.4 wt % CaF2is 247.07 kJ摩尔−1,结晶能量障碍被克服对应CaF2nanocrystals的形成而不是铝硅酸盐的形成,其大小和分布容易使玻璃不透明。同样，FT-IR和XPS结果表明，当caf2的添加量增加到27.4 wt%时，样品的聚合程度更适合钙和氟原子的扩散，只形成caf2纳米晶体；其中，桥氧（Oo）、非桥氧（O−）和自由氧（O2−）的摩尔分数分别约为0.12、0.77和0.11。
The effect of CaF2addition (15.4, 20.4, 27.4 and 35.4 wt%) on the crystallisation ability and preparation of transparent glass ceramics (TGCs) containing CaF2nanocrystals was studied. It was found that samples with 15.4, 20.4, and 35.4 wt% CaF2are crystallised with multiple crystal phases, making the TGCs opaque. Only when the amount of CaF2added is increased to 27.4 wt%, TGCs with only CaF2nanocrystals can be successfully prepared by heat treatment at 630 and 730 °C for 2 h. The crystallisation activation energy of the sample with 27.4 wt% CaF2is 247.07 kJ mol−1, and the crystallisation energy barrier to be overcome corresponds to the formation of CaF2nanocrystals rather than the formation of aluminosilicates, whose size and distribution easily make the glass opaque. Similarly, the FT-IR and XPS results indicate that as the amount of CaF2added is increased to 27.4 wt%, the polymerisation degree of the sample is more suitable for the diffusion of calcium and fluorine atoms to form only CaF2nanocrystals; therein, the corresponding mole fractions of the bridging oxygen (Oo), non-bridging oxygen (O−), and free oxygen (O2−) are approximately about 0.12, 0.77 and 0.11, respectively.