research papers
The relative stability of high-pressure phases of NiSi has been determined by ab initio calculations. Above ∼250 GPa, NiSi adopts the CsCl structure and therefore at the pressures of the Earth's inner core it will be isostructural with FeSi.
Keywords: NiSi; nickel silicide; ab initio calculations; equations of state; high pressure; Earth's core.
research papers
Ice VI is an important rock-forming mineral phase in icy planetary bodies; the pressure and temperature dependence of its density have been measured using powder neutron diffraction, throughout the high-pressure stability field, to obtain an accurate equation of state parameterization. These data are used to derive other thermodynamic quantities of use in planetary modelling.
laboratory notes
A thermoelectrically cooled sample stage for X-ray powder diffraction in the range from about 250 to 300 K is described. The stage is constructed in such a way that it may be removed from the diffractometer and pre-cooled to its base temperature before the sample is loaded.
research papers
The high-pressure structures of NiSi and their room-temperature equations of state have been investigated using synchrotron X-ray diffraction in a diamond anvil cell, coupled with laser annealing. An -FeSi-structured phase was found to form above ∼13 GPa and a CsCl-structured phase above ∼61 GPa.
Keywords: NiSi; nickel silicide; diamond anvil cells; equations of state; high pressure; Earth's core.