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Published in David W. Richerson, William E. Lee, Modern Ceramic Engineering, 2018
David W. Richerson, William E. Lee
Figure 6.29 uses a system containing SiO2 to illustrate the representation of polymorphic forms of a compound on a ternary phase equilibrium diagram. Alpha quartz is stable up to 573°C (1063°F), beta quartz from 573°C to 870°C (1063 to 1598°F), tridymite between 870°C and 1470°C (1598°F and 2678°F), and cristobalite above 1470°C (2678°F). The stable temperature range of each polymorph is therefore indicated by curved lines that coincide with isotherms. However, remember that equilibrium is not always reached in real systems and that metastable polymorphs are commonly encountered, especially in system containing SiO2 and ZrO2.
Quartz Crystal Microbalance–Based Biosensors
Published in Krzysztof Iniewski, Biological and Medical Sensor Technologies, 2017
A large number of crystals exhibit PZ effect, but the electrical, thermal, mechanical, and chemical properties of the quartz make it the most common crystal type used in analytical applications [12]. The quartz crystal is an SiO2 monocrystal with a zinc-blend structure type, present in nature with various forms, α-quartz and β-quartz. Alpha-quartz form is used for PZ applications since this form is insoluble in water and resistant to high temperatures.
Removal of antibiotics from aqueous solution using silicon-based materials. An overview
Published in Environmental Technology Reviews, 2018
Yige Guo, Bin Chen, Dongfang Liu, Wenli Huang, Yu Sun, Ying Zhao
Quartzite (Figure 7(a)) is one kind of the silicon oxide mineral mainly composed by SiO2. Quartzite mineralized under different temperature process two different structures: alpha quartz of trigonal system at low temperature and beta quartz of hexagonal system at high temperature.