Strength and elasticity of SiO₂ across the Stishovite-CaCl₂-type structural phase boundary

Lattice strain measurements under nonhydrostatic compression in a diamond anvil cell were used to examine dense SiO₂. Experiments were performed using energy dispersive x-ray diffraction and solid-state Ge detector fixed at 2θ=12°. The collecting time was 5-30 min for each spectrum. Spectra were collected only after sufficient time elapsed after pressurization such that stress relaxation was observed to be negligible. The data were analyzed using lattice strain theory.