Electron traps in (Y0.97Zr0.03)2O3 transparent ceramics and its suppression by heavy Eu3+ doping

In this paper, Eu3+:(Y0.97Zr0.03)2O3 transparent ceramics with different doping concentrations of Eu3+ were prepared by vacuum sintering. This series of transparent ceramic samples exhibits strong red emission when excited by an electron beam at the keV level. However, color changes observed in the samples after high-energy electron irradiation. This is due to the capture of electrons by traps related to oxygen vacancies within the Y2O3 lattice. Specifically, under electron beam irradiation, the capture of the electrons by oxygen vacancy-related defects in the Y2O3 lattice occurs, leading to radiation damage. The color change can be suppressed to some extent by the incorporation of Zr4+ into the Y2O3 lattice, which can effectively suppress the generation of oxygen vacancies. Interestingly, samples with heavy doping of Eu3+ exhibit stronger resistance to electron irradiation damage. Based on the detailed characterizations, including optical transmittance, cathodoluminescence, photoluminescence, thermoluminescence and luminescence decay time, it is found that under heavy doping conditions, Eu3+, which has a stronger cationic character than Y3+ can more effectively suppress the generation of electron traps induced by the oxygen vacancies and the interstitial oxygen in the Y2O3 lattice, thereby enhancing radiation resistance. This research can advance the understanding of defect suppression mechanisms and benefit the application of Y2O3-based functional transparent ceramics in high-energy electron and beta-ray irradiation environment.