High-pressure phase transitions in Zn1-xMxSe (M=Cd, Fe, and Mn)

Energy-dispersive x-ray diffraction was employed to study pressure-induced phase transitions in Zn0.84Fe0.16Se, Zn0.9Cd0.1Se, and Zn0.76Mn0.24Se crystals up to 21.0, 23.3, and 24.3 GPa, respectively. Our result shows that the B3 to B1 structure transitions for these crystals occurred at 1 1.4 +/- 0.5, 9.5 +/- 0.3, and 9.6 +/- 0.5 GPa, respectively. Compared to the phase-transition pressure (P-t) of ZnSe (14.4 GPa), a reduction of about 3-5 GPa is exhibited in these ternary compounds. This reduction in phase-transition pressure Delta P-t in the ternary compounds suggests that the fractional volume change, (Delta V/V-o), of the B3-B1 phase admixture might be the source of this reduction. Our results indicate that P-t (with respect to the phase transition pressure 14.4 GPa of ZnSe) is related to the fractional volume change (Delta V/V-o) by the expression P-t = [14.4003 + 0.1568 (Delta V/V-o)-0.0281(Delta V/V-o)(2)] GPa. [S0163-1829(98)05426-5].