High-Pressure Study of Perovskites and Postperovskites in the (Mg,Fe)GeO3 System

Camelia V. Stan, Rajkrishna Dutta, Robert J. Cava, Vitali B. Prakapenka, Thomas S. Duffy

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2 Scopus citations

Abstract

The effect of incorporation of Fe2+ on the perovskite (Pbnm) and postperovskite (Cmcm) structures was investigated in the (Mg,Fe)GeO3 system at high pressures and temperatures using laser-heated diamond anvil cell and synchrotron X-ray diffraction. Samples with compositions of Mg# ≥ 48 were shown to transform to the perovskite (∼30 GPa and ∼1500 K) and postperovskite (>55 GPa, ∼1600-1800 K) structures. Compositions with Mg# ≥ 78 formed single-phase perovskite and postperovskite, whereas those with Mg# < 78 showed evidence for partial decomposition. The incorporation of Fe into the perovskite structure causes a decrease in octahedral distortion as well as a modest decrease in bulk modulus (K0) and a modest increase in zero-pressure volume (V0). It also leads to a decrease in the perovskite-to-postperovskite phase transition pressure by ∼9.5 GPa over compositions from Mg#78 to Mg#100.

Original languageEnglish (US)
Pages (from-to)8026-8035
Number of pages10
JournalInorganic Chemistry
Volume56
Issue number14
DOIs
StatePublished - Jul 17 2017

All Science Journal Classification (ASJC) codes

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry

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