Fixed points for pressure calibration above 100 kbars related to semiconductor-metal transitions

Abstract

Pressures assigned to the semiconductor-metal transitions in ZnTe, ZnS, GaAs, and GaP have been determined by detecting the electrical resistance change of the semiconductors while the lattice parameter of standard material NaCl was simultaneously measured with x-ray diffraction techniques. A pressure vessel of the split-octahedron type and various pressure-transmitting media have been employed. Pressures were estimated according to the equation of state for NaCl proposed by Decker. The transition pressures, 1296 kbars for ZnTe, 1557 kbars for ZnS, 1888 kbars for GaAs, and 25310 kbars for GaP, constitute fixed points for pressure calibration above 100 kbars at room temperature.

First-principles study of the orthorhombic mechanism for theB3/B1high-pressure phase transition of ZnS

“…On the other hand, gradient-corrected functionals usually overcorrect the LDA error, leading to the opposite effect of producing too high transition pressures. For the B3/B1 transition of ZnS, experimental results obtained by x-ray diffraction in static compression runs yield p t values in a range from 12 to 18 GPa, [10][11][12][13][14][15][16] which is close to that between our LDA and B3LY P data. The kinetic mechanism of phase transformation was examined, first of all, along the new orthorhombic Pmm2 pathway recently proposed for the same transition of SiC.…”

“…Both ambient pressure polymorphs of ZnS ͑cubic zinc blende and hexagonal wurtzite͒ undergo a phase transition to the rocksalt structure at a comparatively low pressure, with respect to other AB semiconductors, in the range from 12 to 18 GPa according to different authors. [10][11][12][13][14][15][16] It seemed therefore interesting to check the results obtained previously for SiC, with a transition pressure approaching 100 GPa, on zinc sulfide. Further, the electronic and chemical bonding properties along the transformation pathway are investigated in the present case, as well as details of the structural changes of the intermediate states not taken into account in the SiC study.…”

Stability field of phase Egg, AlSiO₃OH at high pressure and high temperature: possible water reservoir in mantle transition zone

“…2). In this research, pressure calibration was conducted using the metallic transition of ZnS (15.5 GPa) and GaAs (18.8 GPa) (Onodera and Ohtani, 1980). The pressure calibration curve at high temperature was obtained based on the wadsleyiteringwoodite (β-γ) transition of Mg 2 SiO 4 , 17.5 GPa at 1000°C and post-spinel boundaries, 23.5 GPa at 1200°C…”

Deformation T-Cup: A new multi-anvil apparatus for controlled strain-rate deformation experiments at pressures above 18 GPa

“…Synchrotron based deformation experiments have been performed at pressure up to 10 GPa, at the NSLS' monochromatic beam-line X17B2ss and offline deformation experiments have been performed at the pressures of the insulator-metal phase changes in ZnS (15.5 GPa) and GaAs (18.8 GPa). 36 A summary of the experiments discussed herein is presented in Table I. In the testing to date, the rate of anvil failure is approximately the same as that in the T-Cup or any other multi-anvil using small sized cubes and the cell design Figure 4.…”