Annihilation behaviors of athermal omega-phase crystals due to electron irradiation

Annihilation behaviors of athermal omega-phase crystals formed by cooling a t 131 K for 10.8 ks under four different electron irradiation conditions of acceleration voltages of 200 kV and 160 kV, and beam currents of approxima tely 20 pA/cm(2) and 5 pA/cm(2) were investigated using in situ dark field and HREM observation methods at 131 K. The effect of acceleration voltages on the lifetimes is recognized, i.e., in the case of approximately equal el ectron beam current, lifetimes at 200 kV become shorter than those at 160 k V. Also, lifetimes depend on the electron beam current at 200 kV, i.e., the higher the beam currents, the shorter the lifetimes become. However, no di stinct dependence can be seen at 160 kV. Since annihilations of athermal om ega-phase crystals begin after the electron irradiation for a certain perio d in each condition, which depends on acceleration voltages and beam curren ts, it is suggested that the annihilation behaviors have incubation periods .