A Comparative Study of Electron Radiation Responses of Pu2Zr2O7 and La2Zr2O7: An ab initio Molecular Dynamics Study

In this study, the response of Pu2Zr2O7 and La2Zr2O7 to electronic radiation is simulated, employing an ab initio molecular dynamics method. It is shown that Pu2Zr2O7 undergoes a crystalline-to-amorphous structural transition with 0.3% electronic excitation, while for La2Zr2O7, the structural amorphization occurs with 1.2% electronic excitation. During the microstructural evolution, the anion disorder further drives cation disorder and eventually results in the structural amorphization of Pu2Zr2O7 and La2Zr2O7. The difference in responses to electron radiation between Pu2Zr2O7 and La2Zr2O7 mainly results from the strong correlation effects between Pu 5f electrons and the smaller band gap of Pu2Zr2O7. These results suggest that Pu2Zr2O7 is less resistant to amorphization under local ionization rates that produce a low level of electronic excitation, since the level of the concentration of excited electrons is relatively low in Pu2Zr2O7. The presented results will advance the understanding of the radiation damage effects of zirconate pyrochlores.

Automated summary

The response of Pu2Zr2O7 and La2Zr2O7 to electronic radiation was simulated using an ab initio molecular dynamics method. Pu2Zr2O7 undergoes crystalline-to-amorphous transition with a lower electronic excitation percentage compared to La2Zr2O7. Anion disorder further drives cation disorder during microstructural evolution, leading to the structural amorphization of both compounds.