|About this Abstract
||Materials Science & Technology 2020
||Emergent Materials under Extremes and Decisive In Situ Characterizations
||High Pressure & Temperature Investigation into Thorium Orthosilicates
||Andrew Charles Strzelecki, Jason Baker, Stella Chariton, Vitali Prakapenka, Hongwu Xu, Mostafa Ahmadzadeh, John McCloy, Paul Estevenon, Adel Mesbah, Nicolas Dacheux, Xiaofeng Guo
|On-Site Speaker (Planned)
||Andrew Charles Strzelecki
The thorium orthosilicate minerals, thorite and huttonite, are isochemical (ThSiO4), but differ in crystal structure. Thorite is isostructural to zircon which is tetragonal and belongs to the I41/amd space group. Huttonite, the high temperature polymorph, is isostructural to monazite being monoclinic and crystallizes into the P21/n space group. Other tetravalent metal orthosilicate, such as ZrSiO4, HfSiO4, and USiO4 are known to exhibit a pressure induced phase transition from the zircon structure to scheelite structure (I41/a). However, ThSiO4 may not have such a transition indicated previously by computational work. The huttonite phase has only been investigated experimentally under elevated temperature conditions. In this presentation we will highlight the first ever experimental work into the pressure induced phase change of thorium orthosilicates utilizing both synchrotron powder x-ray diffraction and Raman spectroscopy. In situ high pressure and high temperature was generated by combination of diamond anvil cells and laser heating.