title: The equation of state of thePmmnphase of NiSi.
abstract: The equation of state of the orthorhombic phase of NiSi withPmmnsymmetry has been determined at room temperature from synchrotron-based X-ray diffraction measurements of its lattice parameters, made in a diamond anvil cell. Measurements were performed up to 44 GPa, using Ne as the pressure medium and Au as the pressure standard. The resulting pressure-volume (P-V) data have been fitted with a Birch-Murnaghan equation of state of third order to yieldV0= 11.650 (7) Å3atom-1,K0= 162 (3) GPa andK0' = 4.6 (2). In addition,P-Vdata have been collected on Ni53Si47in the B20 structure using both Ne and He as the pressure media and Cu and Au as the pressure standards, also to 44 GPa. A fit using the same Birch-Murnaghan equation of state of third order yieldsV0= 11.364 (6) Å3atom-1,K0= 171 (4) GPa andK0' = 5.5 (3).
authors.affiliation: School of Earth Sciences, University of Bristol , Wills Memorial Building, Queen's Road, Bristol BS81RJ, UK.
authors.forename: Oliver T
authors.initials: OT
authors.lastname: Lord
authors.affiliation: School of Earth Sciences, University of Bristol , Wills Memorial Building, Queen's Road, Bristol BS81RJ, UK ; Department of Earth Sciences, University College London , Gower Street, London WC1E 6BT, UK.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Thomson
authors.affiliation: Department of Earth Sciences, University College London , Gower Street, London WC1E 6BT, UK.
authors.forename: Elizabeth T H
authors.initials: ET
authors.lastname: Wann
authors.affiliation: Department of Earth Sciences, University College London , Gower Street, London WC1E 6BT, UK.
authors.forename: Ian G
authors.initials: IG
authors.lastname: Wood
authors.affiliation: Department of Earth Sciences, University College London , Gower Street, London WC1E 6BT, UK.
authors.forename: David P
authors.initials: DP
authors.lastname: Dobson
authors.affiliation: Department of Earth Sciences, University College London , Gower Street, London WC1E 6BT, UK.
authors.forename: Lidunka
authors.initials: L
authors.lastname: Vocadlo
keywords: NiSi; diamond anvil cells; equations of state; high pressure