• journal_title：European Journal of Mineralogy
• Contributor：Shigeaki Ono ; Takumi Kikegawa ; Yasuo Ohishi
• Publisher：E. Schweizerbart'sche Verlagsbuchhandlung Science Publishers
• Date：2007-
• Format：text/html
• Language：en
• Identifier：10.1127/0935-1221/2007/0019-1713
• journal_abbrev：Eur J Mineral
• issn：0935-1221
• volume：19
• issue：2
• firstpage：183
• section：Articles

The compressibility of high-pressure phase FeSi was investigated by in situ high-pressure X-ray powder diffraction. Pressure up to 67 GPa was generated using the diamond anvil cell technique. FeSi transformed to a B2-type structure during laser heating, and remained stable up to the maximum pressure. This first-order phase transformation showed a volume reduction of 4 % at 25 GPa. The fit of a Birch-Murnaghan equation-of-state to the pressure-volume data resulted in V₀ = 21.32 (3) ų and K₀ = 225 (2) GPa when K₀’ was fixed at 4. Our results are in good agreement with those of previous numerical studies using a GGA method employing ab initio calculations. This indicates that a small amount of B2-type FeSi phase may contribute to the decrease in seismic velocity at the base of the lower mantle.