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Post‐oxide phases of forsterite and enstatite
Author(s) -
Liu Lingun
Publication year - 1975
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl002i010p00417
Subject(s) - forsterite , enstatite , periclase , orthorhombic crystal system , perovskite (structure) , materials science , stoichiometry , mineralogy , oxide , phase (matter) , rutile , stishovite , analytical chemistry (journal) , geology , thermodynamics , crystal structure , crystallography , chemistry , metallurgy , spinel , paleontology , physics , meteorite , organic chemistry , chromatography , astronomy , chondrite , quartz
Both forsterite (Mg 2 SiO 4 ) and enstatite (MgSiO 3 ) enter a post‐oxide phase characterized by the orthorhombic perovskite structure when subjected to high pressure and temperature in the diamond‐anvil press coupled with laser heating. The lattice parameters for the perovskite phase of MgSiO 3 are a o = 4.790 ± 0.002, b o = 4.943 ± 0.002, and c o = 6.897 ± 0.003 Å with Z = 4. The calculated density of MgSiO 3 (perovskite) is thus 4.083 g/cm³, or 2.8% denser than its isochemical mixed oxides with rocksalt and rutile structures. The density of a mixture of MgSiO 3 (perovskite) plus MgO (periclase) is 1.9% greater than that of the mixed oxides with the forsterite stoichiometry.