固体地球物理学术报告通知-20170605 于永刚 研究员
Ab-initio computational approach has been applied to reveal properties of interest in single component solid, minerals in solid solutions with high mutual mixability, and insulators that are hard to dope by impurities (e.g. at ppm level). (1) We will briefly describe our previous calculations on thermodynamics and phase transitions in polymorphs of magnesium silicates (Mg2SiO4 and MgSiO3) in the Earth upper mantle and transition zone, and illustrate the phase equilibrium calculations in Fe-bearing olivine and ringwoodite, both of which are of direct impact on the transition zone mineralogy. (2) A comprehensive defect equilibrium calculation for vacancy, interstitial, and anti-side defect in solids at various temperature and chemical condition range will be given to exemplify the methodology that can be useful to study the content of defects and their dominant charge states in dilute solid solutions. Possible applications may include immobilization of radioactive elements and trace elements behavior in solids (e.g. elements of rare Earth).