Crystallographic preferred orientation in wüstite (FeO) through the cubic-to-rhombohedral phase transition
Magnesiowüstite, (Mg 0.08 Fe 0.88 )O, and wüstite, Fe 0.94 O, were compressed to ~36 GPa at ambient temperature in the diamond anvil cell (DAC) at the Advanced Light Source. X-ray diffraction patterns were taken in situ in radial geometry in order to study the evolution of crystallographic preferred...
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Published in | Physics and chemistry of minerals Vol. 39; no. 8; pp. 613 - 626 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Berlin/Heidelberg
Springer-Verlag
01.09.2012
Springer Nature B.V |
Subjects | |
Online Access | Get full text |
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Summary: | Magnesiowüstite, (Mg
0.08
Fe
0.88
)O, and wüstite, Fe
0.94
O, were compressed to ~36 GPa at ambient temperature in the diamond anvil cell (DAC) at the Advanced Light Source. X-ray diffraction patterns were taken in situ in radial geometry in order to study the evolution of crystallographic preferred orientation through the cubic-to-rhombohedral phase transition. Under uniaxial stress in the DAC, {100}
c
planes aligned perpendicular to the compression direction. The {100}
c
in cubic became {
}
r
in rhombohedral and remained aligned perpendicular to the compression direction. However, the {101}
c
and {111}
c
planes in the cubic phase split into {
}
r
and {
}
r
, and (0001)
r
and {
}
r
, respectively, in the rhombohedral phase. The {
}
r
planes preferentially aligned perpendicular to the compression direction while {
}
r
oriented at a low angle to the compression direction. Similarly, {
}
r
showed a slight preference to align more closely perpendicular to the compression direction than (0001)
r
. This variant selection may occur because the 〈
〉
r
and [0001]
r
directions are the softer of the two sets of directions. The rhombohedral texture distortion may also be due to subsequent deformation. Indeed, polycrystal plasticity simulations indicate that for preferred {
}〈
〉
r
and {
}〈
〉
r
slip and slightly less active {
}〈
〉
r
slip, the observed texture pattern can be obtained. |
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ISSN: | 0342-1791 1432-2021 |
DOI: | 10.1007/s00269-012-0516-x |