Skip to Main Content
Skip Nav Destination
GEOREF RECORD

High-pressure and high-temperature phase transitions in FeTiO (sub 3) and a new dense FeTi (sub 3) O (sub 7) structure

Daisuke Nishio-Hamane, Zhang Meiguang, Takehiko Yagi and Ma Yanming
High-pressure and high-temperature phase transitions in FeTiO (sub 3) and a new dense FeTi (sub 3) O (sub 7) structure
American Mineralogist (April 2012) 97 (4): 568-572

Abstract

High-pressure and high-temperature phase relations of FeTiO (sub 3) were investigated up to a pressure of about 74 GPa and 2600 K by synchrotron X-ray diffraction and analytical transmission electron microscopy. We conclude that FeTiO (sub 3) ilmenite transforms into the following phase(s) with increasing pressure: FeTiO (sub 3) (perovskite) at 20-30 GPa, Fe (sub 2) TiO (sub 4) (Ca (sub 2) TiO (sub 4) -type)+TiO (sub 2) (OI-type) at 30-44 GPa and high temperature, FeO(wustite)+TiO (sub 2) (OI) at 30-44 GPa and low temperature, and wustite+FeTi (sub 3) O (sub 7) (orthorhombic phase) above 44 GPa. Among these dense high-pressure polymorphs, FeTi (sub 3) O (sub 7) is a new compound and its structure analysis was tried using particle swarm optimization simulation. This method successfully found a new high-density FeTi (sub 3) O (sub 7) structure, and Rietveld refinement based on this model structure gave an excellent fit with the experimentally obtained X-ray diffraction pattern. This new high-density FeTi (sub 3) O (sub 7) structure consists of polyhedra for monocapped FeO (sub 7) prisms, bicapped TiO (sub 8) prisms, and tricapped TiO (sub 9) prisms, which develop on the b-c plane and stack along the a axis. The dense compound assemblage found in FeTiO (sub 3) is promising for investigating the behavior of ABX (sub 3) compounds under ultrahigh pressures.


ISSN: 0003-004X
EISSN: 1945-3027
Coden: AMMIAY
Serial Title: American Mineralogist
Serial Volume: 97
Serial Issue: 4
Title: High-pressure and high-temperature phase transitions in FeTiO (sub 3) and a new dense FeTi (sub 3) O (sub 7) structure
Affiliation: University of Tokyo, Institute for Solid State Physics, Tokyo, Japan
Pages: 568-572
Published: 201204
Text Language: English
Publisher: Mineralogical Society of America, Washington, DC, United States
References: 32
Accession Number: 2012-041838
Categories: Geophysics of minerals and rocks
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 2 tables
Secondary Affiliation: Jilin University, CHN, China
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Abstract, copyright, Mineralogical Society of America. Reference includes data from GeoScienceWorld, Alexandria, VA, United States
Update Code: 201222
Close Modal

or Create an Account

Close Modal
Close Modal