<p>Jeffbenite is a magnesium aluminosilicate phase (nominally Mg<sub>3</sub>Al<sub>2</sub>Si<sub>3</sub>O<sub>12</sub>) found naturally in close association with diamonds. It has been synthesized at pressures as low as 6.5 GPa. We report here the synthesis of crystalline jeffbenite solid solutions at ambient pressure, through the controlled crystallization of glass. The resulting glass-ceramic materials can have between 20 and over 60 wt% crystalline jeffbenite. X-ray diffraction, <sup>27</sup>Al NMR, Raman spectral analysis, density, and elastic property evaluation all support the identification of this phase precipitating from glass. A mechanism for the nucleation and formation of this high-pressure phase, at ambient pressure conditions, is presented. Glass-ceramics based on jeffbenite may be transparent or opaque, have high modulus and hardness, and can be strengthened by ion exchange for a possible range of technical uses.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Formation of the high pressure jeffbenite phase from glass at ambient pressure

  • Charlene M. Smith,
  • George H. Beall,
  • John P. Finkeldey

摘要

Jeffbenite is a magnesium aluminosilicate phase (nominally Mg3Al2Si3O12) found naturally in close association with diamonds. It has been synthesized at pressures as low as 6.5 GPa. We report here the synthesis of crystalline jeffbenite solid solutions at ambient pressure, through the controlled crystallization of glass. The resulting glass-ceramic materials can have between 20 and over 60 wt% crystalline jeffbenite. X-ray diffraction, 27Al NMR, Raman spectral analysis, density, and elastic property evaluation all support the identification of this phase precipitating from glass. A mechanism for the nucleation and formation of this high-pressure phase, at ambient pressure conditions, is presented. Glass-ceramics based on jeffbenite may be transparent or opaque, have high modulus and hardness, and can be strengthened by ion exchange for a possible range of technical uses.