The tetragonal to orthorhombic ferroelastic phase transition between rutile-and CaCl 2-type
SiO 2 at high pressures is studied using first-principles calculations and the Landau free …

4.1 Introduction 51 4.2 Elastic constants 52 4.3 Isothermal versus adiabatic elastic constants
55 4.4 Experimental techniques 57 4.5 Some general trends in elasticity: Birch's law 59 4.6 …

The high-pressure phase diagram of Si O 2 has been calculated using density-functional
perturbation theory. We find that phase transitions of silica do not correspond to any …

We report high pressure polymorphism of SiO2 and GeO2 at room and high temperatures. It
was found that kinetics has a large effect on pressure induced phase transitions of SiO2 and …

The distribution and transportation of water in Earth's interior depends on the stability of
water-bearing phases. The transition zone in Earth's mantle is generally accepted as an …

This article summarizes the developments of experimental techniques for high pressure x-
ray diffraction (XRD) in diamond anvil cells (DACs) using synchrotron radiation. Basic …

Seismic studies have found seismic scatterers with− 2 to− 12% shear velocity anomalies
along some subducting slabs at 700–1900 km depth. The ferroelastic post‐stishovite …

We perform first principles calculations of three ordered high‐pressure polymorphs of silica
to investigate their phase equilibrium: stishovite, CaCl2 and α‐PbO2. We use the density …

The elastic constant tensors of stishovite and the CaCl 2-type silica at the Earth's mantle
temperature and pressure were determined using first-principles calculations with local …

We review recent advances in the study of phase transitions of minerals in the Earth's
mantle, including unsolved problems regarding these processes. The phase boundaries of …