| About this Abstract |
| Meeting |
MS&T21: Materials Science & Technology
|
| Symposium
|
Phase Transformations in Ceramics: Science and Applications
|
| Presentation Title |
High Pressure Phase Transformations of Zircon-type Silicate Materials |
| Author(s) |
Xiaofeng Guo, Andrew Strzelecki, Xiaodong Zhao, Jason Baker, Stella Chariton, Vitali Prakapenka, Hongwu Xu |
| On-Site Speaker (Planned) |
Xiaofeng Guo |
| Abstract Scope |
Understanding the crystallographic transformations of zircon-type silicate materials under pressure have wide and important implications in their application as nuclear waste forms, as high temperature coating materials, and for geochemical mineralization. The orthosilicate mineral zircon (ZrSiO4) with its tetragonal crystal structure, crystallizing into the I41/amd space group. Ce, Th, U can also crystalize into zircon structure, forming coffinite, thorite, and stetindite, respectively. Although ZrSiO4 and HfSiO4 are known to exhibit a pressure-induced phase transition from the zircon structure (I41/amd) to scheelite structure (I41/a1), the high pressure phase diagrams for other tetravalent 4f/5f metal orthosilicate are more ambiguous and may have alternative routes to P21/n or C2/c phases. Here we reported in situ high pressure synchrotron powder x-ray diffraction and Raman spectroscopy implemented with diamond anvil cells on Ce, Th, U bearing orthosilicate to reveal their transformation under hydrostatic compression. Equations of state of these silicate materials were also reported. |