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High Pressure Properties of the Alkaline‐Earth Sulphides
Author(s) -
van Camp P. E.,
van Doren V. E.,
Martins J. L.
Publication year - 1995
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2221900127
Subject(s) - pseudopotential , alkaline earth metal , lattice constant , bulk modulus , ab initio , thermodynamics , chemistry , phase transition , moduli , phase (matter) , materials science , alkali metal , condensed matter physics , physics , organic chemistry , diffraction , quantum mechanics , optics
The alkaline‐earth sulphides MgS, CaS, SrS, and BaS naturally occur in the rocksalt (Bl) structure. Under pressure they undergo a structural phase transformation to the cesiumchloride (B2) structure. Ab‐initio local density nonlocal pseudopotential calculations of the total energy of the first three compounds are performed in the B1, B2, and in the zincblende (B3) structure. It is found that the B1 structure is stable at normal conditions while the B3 structure is unstable under all conditions. The B1 to B2 phase transformation occurs at, respectively, 230.7, 49.8, and 20.9 GPa. Recent experimental estimates of these transition pressures are 44 and 37.1 GPa for CaS. The calculated lattice constants, bulk moduli, and their pressure derivatives agree well with the experimental values.