• journal_title：American Mineralogist
• Contributor：Pascal Schouwink ; Leonid Dubrovinsky ; Konstantin Glazyrin ; Marco Merlini ; Michael Hanfland ; Thomas Pippinger ; Ronald Miletich
• Publisher：Mineralogical Society of America
• Date：2011-
• Format：text/html
• Language：en
• Identifier：10.2138/am.2011.3775
• journal_abbrev：American Mineralogist
• issn：0003-004X
• volume：96
• issue：11-12
• firstpage：1781
• section：Articles

In situ X-ray diffraction experiments were carried out at pressures up to 25 GPa on a synthetic hematite (α-Fe₂O₃) crystal using synchrotron radiation in an angle-dispersive setup. Experiments were performed in diamond-anvil cells using neon as a pressure-transmitting medium. Single-crystal diffraction data were collected from omega scans and structural refinements were carried out for 10 pressure points. Bulk and linear incompressibilities were obtained from least-squares fits of refined data to the Eulerian strain based Birch-Murnaghan equation of state. Finite strain analysis suggests a truncation at second order, yielding results of K₀ = 207(3), K_a0 = 751(17), and K_c0 = 492(8) for bulk and axial moduli, respectively. The a-axis is about 1.5 times stiffer than the c-axis. Compression of the main structural feature, the FeO₆ octahedra, is quite uniform, with just slight changes of distortion parameters at higher pressures.