title: Observation of cation reordering during the olivine-spinel transition in fayalite by in situ synchrotron X-ray diffraction at high pressure and temperature.
abstract: The olivine-spinel phase transition in fayalite at high pressure and temperature has been studied using time-resolved x-ray diffraction. Structure refinements show a delay of cation reordering relative to anions during the phase transformation and an increase in the cell volume while the cations reorder into their sites. A significant stress drop in the sample is observed. This experiment, for the first time, quantitatively demonstrates a pseudomartensitic transformation: a diffusionless anion sublattice transition coupled with short-range diffusional cation reordering.
authors.affiliation: Center for High Pressure Research, Department of Geosciences, State University of New York at Stony Brook, Stony Brook, New York 11794-2100, USA.
authors.forename: J
authors.initials: J
authors.lastname: Chen
authors.forename: D J
authors.initials: DJ
authors.lastname: Weidner
authors.forename: J B
authors.initials: JB
authors.lastname: Parise
authors.forename: M T
authors.initials: MT
authors.lastname: Vaughan
authors.forename: P
authors.initials: P
authors.lastname: Raterron