Structural integrity and damage of glass-ceramics after He ion irradiation: Insights from ZrO2-SiO2 nanocrystalline glass-ceramics

Developing new radiation-resistant materials and understanding the structural damages caused by radiation are persistent goals of material scientists. Here, we report on the structural integrity and damage to ZrO2-SiO2 nanocrystalline glass-ceramics after radiation with 1.4 MeV He ions at three different fluences: 1.0 x 1016 ions/ cm2 (low), 5.0 x 1016 ions/cm2 (moderate), and 1.0 x 1017 ions/cm2 (high) at 500 degrees C. Grazing incident X-ray diffraction shows the tetragonal-ZrO2 to monoclinic-ZrO2 phase transformation induced by microstrain from the irradiation. The addition of yttrium indicated tetragonal-ZrO2 stabilization effect during irradiation. The irra-diated glass-ceramics show a Raman signal-enhancement effect probably related to the electronic structure changes of the amorphous SiO2 component in the glass-ceramics. The formation of microcracks and lattice de-fects within ZrO2 nanocrystallites is the main structural damage caused by irradiation. There was no observable amorphization of ZrO2 nanocrystallites due to irradiation. No obvious He bubbles were detected, either. The formation of microcracks results in a decrease of in the nanohardness of the glass-ceramics. The results provide fundamental experimental data to understand the structural integrity and damage caused by radiation, which could be useful to design radiation-resistant nanocrystalline glass-ceramics for extremely radioactive environments.

Automated summary

Developing radiation-resistant materials and understanding structural damage caused by radiation are important goals for material scientists. In this study, ZrO2-SiO2 nanocrystalline glass-ceramics were irradiated with 1.4 MeV He ions at different fluences, and the resulting structural integrity and damage were investigated. The results showed that microstrain from the irradiation induced a phase transformation in the ZrO2 crystals, while the addition of yttrium stabilized the tetragonal-ZrO2 phase. Raman spectroscopy indicated changes in the electronic structure of the amorphous SiO2 component, and microscopy revealed the formation of microcracks and lattice defects as the main structural damage.