High-pressure phase transitions and equations of state in NiSi. I. Ab initio simulations

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.

High-pressure phase transitions and equations of state in NiSi. II. Experimental results

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 [epsilon]-FeSi-structured phase was found to form above ∼13 GPa and a CsCl-structured phase above ∼61 GPa.