TY - JOUR
T1 - Phase relations in Mg3Al2Si3 O12 to 180 GPa
T2 - Effect of Al on post-perovskite phase transition
AU - Tateno, Shigehiko
AU - Hirose, Kei
AU - Sata, Nagayoshi
AU - Ohishi, Yasuo
PY - 2005/8/16
Y1 - 2005/8/16
N2 - Phase relations in Mg3Al2Si3 O12 (MgSiO3 + 25 mol% Al2O3; pyrope garnet composition) were investigated on the basis of in-situ synchrotron X-ray diffraction measurements at high-pressure and -temperature in a laser-heated diamond anvil cell (LHDAC). Results demonstrate that perovskite is solely stable up to 140 GPa and 2200 K, and perovskite and CaIrO3-type post-perovskite phase (space group: Cmcm) coexist above 140 GPa and 2200 K. Post-perovskite is formed as a single phase above 150-170 GPa. Previous study has shown that pure MgSiO3 perovskite transforms to post-perovskite phase above 125 GPa and 2500 K based on the same pressure standard. These results indicate that addition of Al2O3 expands the stability of MgSiO3 perovskite relative to post-perovskite.
AB - Phase relations in Mg3Al2Si3 O12 (MgSiO3 + 25 mol% Al2O3; pyrope garnet composition) were investigated on the basis of in-situ synchrotron X-ray diffraction measurements at high-pressure and -temperature in a laser-heated diamond anvil cell (LHDAC). Results demonstrate that perovskite is solely stable up to 140 GPa and 2200 K, and perovskite and CaIrO3-type post-perovskite phase (space group: Cmcm) coexist above 140 GPa and 2200 K. Post-perovskite is formed as a single phase above 150-170 GPa. Previous study has shown that pure MgSiO3 perovskite transforms to post-perovskite phase above 125 GPa and 2500 K based on the same pressure standard. These results indicate that addition of Al2O3 expands the stability of MgSiO3 perovskite relative to post-perovskite.
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U2 - 10.1029/2005GL023309
DO - 10.1029/2005GL023309
M3 - Article
AN - SCOPUS:25844494339
VL - 32
JO - Geophysical Research Letters
JF - Geophysical Research Letters
SN - 0094-8276
IS - 15
M1 - L15306
ER -