Iron oxidation state of FeTiO[subscript 3] under high pressure

Journal Article · Thu Aug 13 04:00:00 EDT 2009 · Phys. Rev. B

DOI:https://doi.org/10.1103/PhysRevB.79.094106· OSTI ID:1005761

Wu, X; Steinle-Neumann, G; Narygina, O; Kantor, I; McCammon, C; Pascarelli, S; Aquilanti, G; Prakapenka, V; Dubrovinsky, L

The oxidation state of iron in FeTiO{sub 3} under high pressure was investigated by combining x-ray diffraction, Moessbauer spectroscopy, x-ray-absorption spectroscopy, and density-functional theory based calculations. Our results demonstrate that the ilmenite-to-perovskite phase transition occurs above 20 GPa at room temperature and on compression two phases coexist to 40 GPa. The Fe{sup 3+}/{Sigma}Fe ratio increases up to 16 GPa, probably attributed to the d-electron drifting of cations via the oxygen bridge in the adjacent octahedral, then decreases at higher pressure due to the ilmenite-to-perovskite phase transition accompanied by a slight decrease in iron valence state. Our ab initio calculations further show that the most significant changes in the charge distribution in FeTiO{sub 3} are associated with Ti and O.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: USDOE
• OSTI ID: 1005761
• Journal Information: Phys. Rev. B, Journal Name: Phys. Rev. B Journal Issue: (9) ; 2009 Vol. 79; ISSN 1098-0121
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

36 MATERIALS SCIENCE
CHARGE DISTRIBUTION
DENSITY FUNCTIONAL METHOD
IRON COMPOUNDS
PHASE TRANSFORMATIONS
PRESSURE RANGE GIGA PA
SPECTROSCOPY
TITANATES
VALENCE
X-RAY DIFFRACTION