Framework structures are ubiquitous and include the feldspars and perovskites, major components of the Earth's crust and mantle, respectively. Perovskites also have one of the most technologically important structure-types used for electronic materials, including superconductors, gmr, ferroelastics and ferroelectric device materials. This project will use single-crystal X-ray diffraction to determine high-precision structure measurements of framework solid solutions in situ at high pressure in order to elucidate the elastic and thermodynamic effects of various element and defect substitutions into end-members. These detailed studies will lay the basis for developing predictive models for the high-pressure behavior of feldspars and perovskites, as well as other complex framework minerals, including garnets and titanites. The results obtained with this grant will therefore provide fundamental insights and constraints on the geochemistry and mineralogy of the Earth's interior, as well as having widespread application in materials sciences. The award of this grant will also support the training of scientists at all levels, including the hosting of a crystallography workshop each year for students and faculty from regional undergraduate institutions.
