@article{5583eec36a7f467f9fe4ae9e752d5708,
title = "Synthesis and equation of state of perovskites in the (Mg, Fe)3Al2Si3O12 system to 177GPa",
abstract = "Natural and synthetic pyrope-almandine compositions from 38 to 100 mol% almandine (Alm38-Alm100) werestudied by synchrotron X-ray diffraction in the laser-heate ddiamond anvil cell to 177 GPa. Single-phase orthorhombic GdFeO3-type perovskites were synthesized across the entire examined compositional range at deep lower mantle pressures, with higher Fe-contents requiring higher synthesis pressures. The formation of perovskite with Alm100 (Fe3Al2Si3O12) composition at 80 GPa marks the first observation of asilicateperovskiteinaFe end-member.Fe- enrichment broadens and lowers the pressurerange of the post-perovskite transition for intermediate compositions suchas Alm54, but the more Fe-richAlm100-composition perovskite remains stable to pressures as highas 149 GPa. Volume compression data for the Alm54 and Alm100 compositions were fit to the Birch-Murnaghan equation of state. The compressibility of perovskites synthesized from compositions long the pyrope-almandine join is not strongly sensitive to Fecontent. The compression curves were smooth over the entire measured range, and no evidence for a volume anomaly associated with a spin transition was observed.",
keywords = "D″; region, Lower mantle, Perovskite, Post-perovskite",
author = "Dorfman, {Susannah M.} and Shieh, {Sean R.} and Yue Meng and Prakapenka, {Vitali B.} and Duffy, {Thomas S.}",
note = "Funding Information: This work was supported by the NSF and the Carnegie-DOE alliance center. We thank Z. Mao and J. Wang for their experimental assistance. L. Stixrude provided phase equilibria and seismic properties of pyrope, almandine and intermediate compositions simulated with the HeFESTo software. A. Hofmeister and H. O'Neill kindly provided natural and synthetic garnet samples. Diffraction analysis of starting materials was carried out at the PRISM Imaging and Analysis Center which is supported in part by the NSF MRSEC program through the Princeton Center for Complex Materials (Grant DMR-0819860 ). We thank E.E. Alp and L. Gao for assistance with M{\"o}ssbauer spectroscopy of starting materials. Conventional M{\"o}ssbauer spectroscopy at the Advanced Photon Source (APS), Argonne National Laboratory is supported by the Consortium for Materials Properties Research in Earth Sciences (COMPRES). High-pressure gas loading was supported by COMPRES and GeoSoilEnviroCARS. P. Dera, I. Kantor, A. Kubo, B. Lavina, S. Tkachev, and K. Zhuravlev assisted with beamline operations. Experiments were performed at GeoSoilEnviroCARS (Sector 13) and High Pressure Collaborative Access Team (HPCAT, Sector 16) at the APS. GeoSoilEnviroCARS is supported by the NSF - Earth Sciences (EAR-1128799) and DOE - Geosciences (DE-FG02-94ER14466). HPCAT is supported by CIW, CDAC, UNLV and LLNL through funding from DOE-NNSA and DOE-BES, with partial instrumentation funding by NSF. Use of the APS was supported by the U.S. Department of Energy , Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. ",
year = "2012",
month = dec,
day = "1",
doi = "10.1016/j.epsl.2012.09.024",
language = "English (US)",
volume = "357-358",
pages = "194--202",
journal = "Earth and Planetary Science Letters",
issn = "0012-821X",
publisher = "Elsevier",
}