TY - JOUR
T1 - Single crystal synthesis of δ-(Al,Fe)OOH
AU - Kawazoe, Takaaki
AU - Ohira, Itaru
AU - Ishii, Takayuki
AU - Boffa Ballaran, Tiziana
AU - McCammon, Catherine
AU - Suzuki, Akio
AU - Ohtani, Eiji
N1 - Funding Information:
We are grateful to R. Njul, Y. Ito, and H. Fischer for their support in sample polishing, chemical analysis and manufacturing of cell assembly parts, respectively. We thank A. Shatskiy and two anonymous reviewers for helpful reviews. This study was supported by the International Research Training Group “Deep Earth Volatile Cycles” funded by the German Research Foundation (DFG) and the Japan Society for the Promotion of Science (JSPS) and by the JSPS Japanese-German Graduate Externship.
Publisher Copyright:
© 2017 by Walter de Gruyter Berlin/Boston.
PY - 2017/9/1
Y1 - 2017/9/1
N2 - Single crystals of δ-AlOOH, δ-(Al0.953,Fe0.047)OOH, and δ-(Al0.878,Fe0.122)OOH with dimensions up to ~0.4-0.6 mm were synthesized by the high-pressure hydrothermal method. Synthesis experiments were performed at 21 GPa and 1470 K for 4 h using a Kawai-type multi-anvil apparatus. The crystals of δ-AlOOH, δ-(Al0.953,Fe0.047)OOH, and δ-(Al0.878,Fe0.122)OOH were colorless, yellowish green, and brown, respectively. Mössbauer spectra showed 95-100% Fe3+/aFe at the octahedral site in δ-(Al,Fe)OOH. Chemical compositions of δ-(Al0.953,Fe0.047)OOH and δ-(Al0.878,Fe0.122)OOH are homogeneous with Fe/(Al+Fe) of 0.0469(8) and 0.122(3), respectively. Unit-cell parameters of δ-AlOOH are consistent with those of previous studies, and they increase with Fe/(Al+Fe). These results confirm that δ-AlOOH can form a solid solution with ϵ-FeOOH. The crystals contained a small number of fluid inclusions. The syntheses of large single crystals of δ-(Al,Fe)OOH will facilitate investigation of their phase stability, physical properties including elasticity and elastic anisotropy, behavior of hydrogen bonding, and spin state of Fe, which will improve models of the water and oxygen cycles in the deep Earth.
AB - Single crystals of δ-AlOOH, δ-(Al0.953,Fe0.047)OOH, and δ-(Al0.878,Fe0.122)OOH with dimensions up to ~0.4-0.6 mm were synthesized by the high-pressure hydrothermal method. Synthesis experiments were performed at 21 GPa and 1470 K for 4 h using a Kawai-type multi-anvil apparatus. The crystals of δ-AlOOH, δ-(Al0.953,Fe0.047)OOH, and δ-(Al0.878,Fe0.122)OOH were colorless, yellowish green, and brown, respectively. Mössbauer spectra showed 95-100% Fe3+/aFe at the octahedral site in δ-(Al,Fe)OOH. Chemical compositions of δ-(Al0.953,Fe0.047)OOH and δ-(Al0.878,Fe0.122)OOH are homogeneous with Fe/(Al+Fe) of 0.0469(8) and 0.122(3), respectively. Unit-cell parameters of δ-AlOOH are consistent with those of previous studies, and they increase with Fe/(Al+Fe). These results confirm that δ-AlOOH can form a solid solution with ϵ-FeOOH. The crystals contained a small number of fluid inclusions. The syntheses of large single crystals of δ-(Al,Fe)OOH will facilitate investigation of their phase stability, physical properties including elasticity and elastic anisotropy, behavior of hydrogen bonding, and spin state of Fe, which will improve models of the water and oxygen cycles in the deep Earth.
KW - high-pressure synthesis
KW - hydrous mineral
KW - Kawai-type multi-anvil apparatus
KW - single crystal
KW - water
KW - δ-(Al,Fe)OOH
KW - δ-AlOOH
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U2 - 10.2138/am-2017-6153
DO - 10.2138/am-2017-6153
M3 - Article
AN - SCOPUS:85029384036
SN - 0003-004X
VL - 102
SP - 1953
EP - 1956
JO - American Mineralogist
JF - American Mineralogist
IS - 9
ER -