Effect of Am-241 Irradiation on ZnO Crystallinity with Different Annealing Temperature

Am-241 is an alpha emitting isotope which can be used to fuel a nuclear battery via alphavoltaic effect by using a semiconductor to convert alpha radiation to electricity. The main issue of alphavoltaic battery is the radiation damage due to high energy alpha particle, resulted in a rapid decline in performance. Zinc oxide (ZnO) is known as a semiconductor with high radiation tolerance. In this study, the effect of annealing temperature to ZnO crystal was studied along with its alteration due to Am-241 irradiation overtime. The annealing temperatures were set at 450°C and 650°C. The irradiation process was carried out using Am-241 isotope for 12 days with an activity of 44.85 mCi and approximately 0.0866 MGy of absorbed dose. The crystal structure of fabricated and irradiated ZnO were investigated through X-ray Diffraction (XRD). The XRD diffraction pattern indicates that the crystal structure of ZnO is hexagonal wurtzite and still maintained after irradiation process. Raising the annealing temperature from 450°C to 650°C leads to a reduction in peak intensity. This change correlates with an increase in grain size post-irradiation. After exposure to alpha particle radiation, changes occurred in the diffraction peaks of ZnO. At 450°C annealing temperature, the intensity decreased by 94.822%, while at 650°C annealing temperature, the intensity decrease was 85.489%. This shows that increasing the annealing temperature can reduce the decrease in intensity after irradiation with alpha particles. The (002) plane shifted by 0.057˚ at 450°C annealing temperature and by 0.042˚ at 650°C after irradiation. In addition, the crystal lattice parameters increased after irradiation, which led to a change in the FWHM value and an increase in the crystal grain size.