• journal_title：American Mineralogist
• Contributor：Alan B. Woodland ; Daniel J. Frost ; Dmytro M. Trots ; Kevin Klimm ; Mohamed Mezouar
• Publisher：Mineralogical Society of America
• Date：2012-
• Format：text/html
• Language：en
• Identifier：10.2138/am.2012.4270
• journal_abbrev：American Mineralogist
• issn：0003-004X
• volume：97
• issue：10
• firstpage：1808
• section：Letters

In situ synchrotron X-ray powder diffraction measurements using a Paris-Edinburgh pressure cell were performed to investigate the nature of the high-pressure breakdown reaction of magnetite (Fe₃O₄). Refinement of diffraction patterns reveals that magnetite breaks down via a disproportionation reaction to Fe₄O₅ and hematite (Fe₂O₃) rather than undergoing an isochemical phase transition. This result, combined with literature data indicates (1) that this reaction occurs at ~9.5–11 GPa and 973–1673 K, and (2) these two phases should recombine at yet higher pressures to produce an h-Fe₃O₄ phase.