摘要
Energy-dispersive x-ray diffraction was employed to study pressure-induced phase transitions in (Formula presented)Se, (Formula presented)Se, and (Formula presented)Se crystals up to 21.0, 23.3, and 24.3 GPa, respectively. Our result shows that the (Formula presented) to (Formula presented) structure transitions for these crystals occurred at 11.4(Formula presented)0.5, 9.5(Formula presented)0.3, and 9.6(Formula presented)0.5 GPa, respectively. Compared to the phase-transition pressure (Formula presented) of ZnSe (14.4 GPa), a reduction of about 3-5 GPa is exhibited in these ternary compounds. This reduction in phase-transition pressure (Formula presented) in the ternary compounds suggests that the fractional volume change, (Formula presented), of the (Formula presented) phase admixture might be the source of this reduction. Our results indicate that (Formula presented) (with respect to the phase transition pressure 14.4 GPa of ZnSe) is related to the fractional volume change (Formula presented) by the expression (Formula presented)=[14.4003+0.1568(Formula presented)-0.0281(Formula presented)] GPa. © 1998 The American Physical Society.