Otto-Schott-Institut für Materialforschung, Jena University , Fraunhoferstraβe 6, 07743 Jena, Germany.
Laboratory of Infrared Materials and Devices, Research Institute of Advanced Technology, Ningbo University , Ningbo 315211, China.
Nano Lett. 2015 Oct 14;15(10):6764-9. doi: 10.1021/acs.nanolett.5b02605. Epub 2015 Aug 31.
Transparent bulk glass-ceramics containing ZnF2, K2SiF6, and KZnF3 nanocrystals are successfully obtained from xKF-xZnF2-(100 - 2x)SiO2 oxyfluoride glasses for the first time to the best of our knowledge. The glass transition temperatures of heat-treated samples increase with time and approach values that resemble the temperatures chosen for thermal treatment. During nucleation and crystal growth, the residual glass around the crystals is depleted in fluoride which as glass component usually leads to a decrease in viscosity. The crystallization behavior notably depends on the glass composition and changes within a small range from x = 20 to 22.5 mol %. The occurrence of liquid/liquid phase separation in dependence of the composition is responsible for the physicochemical changes. Two different microstructures of droplet and interpenetrating phase separation and their compositional evolution are observed by replica transmission electron microscopy technique in the multicomponent glassy system. This study suggests that the size and crystal phase of precipitated crystallites can be controlled by the initial phase separation.
据我们所知，首次成功地从 xKF-xZnF2-(100-2x)SiO2 氧氟玻璃中获得了含有 ZnF2、K2SiF6 和 KZnF3 纳米晶的透明块状玻璃陶瓷。热处理样品的玻璃化转变温度随时间的增加而增加，并接近为热处理选择的温度。在成核和晶体生长过程中，晶体周围的残余玻璃中氟化物耗尽，而氟化物通常作为玻璃成分会导致粘度降低。结晶行为显著取决于玻璃成分，并在 20 到 22.5 mol% 的小范围内变化。组成依赖性的液/液相分离的发生是造成物理化学变化的原因。在多组分玻璃系统中，通过复制透射电子显微镜技术观察到液滴和互穿相分离的两种不同微观结构及其组成演变。这项研究表明，沉淀晶体的尺寸和晶体相可以通过初始相分离来控制。
