Hysteresis in the high pressure transformation of bcchyphen; to hcphyphen;iron

摘要

The agr;hyphen;Fe/egr;hyphen;Fe phase transformation has been studied by the Mouml;ssbauer effect of57Fe in a diamond anvil cell at hydrostatic pressures up to 24 GPa. The agr;/egr; composition is easily derived as a function of intermediate pressure. For rising pressures the transition onset is about 9 GPa and half of the agr;hyphen;Fe is converted to egr;hyphen;Fe by 15 GPa; for lowering pressures half of the egr;hyphen;Fe is converted to agr;hyphen;Fe by 9 GPa. The transition pressures, widths, and hysteresis widths are compared to those obtained by other techniques.