纳米多晶柯石英的高温高压合成

Synthesis of Nano-Polycrystalline Coesite under High Temperature and High Pressure

利用国产铰链式六面顶压机,以高纯微米晶α-SiO_2为原料,在5GPa、1000℃条件下实现了微米晶α-SiO_2向柯石英多晶体的直接转变,合成出了纳米多晶柯石英块体,X射线衍射分析表明,该块体材料仅含柯石英单相。扫描电镜显示颗粒的平均尺寸为100nm左右。显微硬度为1406 MPa。

Nano-polycrystalline coesite block has been synthesized by domestic hinge type cubic press by using high-purity micrometer α-SiO2 as raw material under 5 GPa and 1000℃. In this process, the micrometer α-SiO2 has been transformed directly into coesite polycrystat. X-ray diffraction analysis indicates that the bulk material contains coesite sin- gle phase only. The scanning electron microscopic picture shows that the average size of the synthesized coesite crystal is about 100 nm with a microhardness of 1406 MPa. Keywords.high temperature and high pressure; coesite monocrystal; nano-polycrystalline coesite; hinge-type cubic press