Solid-state NMR of high-pressure minerals
We are interested in utilising solid-state NMR to study the structure and properties of the minerals which play an important role in the Earth’s crust and mantle.
Current projects involve the use of 17O NMR for studying high-pressure silicate phases, such as wadsleyite and ringwoodite, which are present at depths of 400-600 km. These minerals are challenging to synthesise, and only small amounts of material can be prepared. The necessitates the use of more sensitive experiments such as STMAS and CPMG.
17O MQMAS spectrum of MgSiO3 orthoenstatite showing 6 distinct oxygen species
We are also studying the incorporation of water/hydrogen into the nominally anhydrous magnesium silicates found in the mantle, through a combination of multinuclear (17O, 25Mg, 29Si, 2H, 1H, 19F) NMR and first-principles calculations. The effects of water incorporation on the physical and chemical properties of the Earth’s mantle are of great interest in geology. Minerals such as humites and amphiboles provide useful models which can be used to understand mechanisms for water storage within magnesium silicates.
