Change in the phase stability of zinc blende and wurtzite on grinding

Abstract

Two different zinc blende (ZB) powders were vibro-milled and the transformation process into the wurtzite (WZ) phase on subsequent heating in N₂ was observed. Vibro-milled ZB transformed rapidly into WZ at the beginning of the heating. Part of the WZ was then retransformed into ZB leaving a large amount of WZ, the reaction attaining an apparent equilibrium state. The transition took place even at 1023 K, which is more than 200 K lower than the lowest ZB ⇌ WZ transition temperature ever reported. The results were interpreted on the assumption of an increase in the chemical potential and a broadening of the chemical potential distribution within the powder mass caused by the mechanical treatment.