Fabrication and luminescent properties of uranium doped Y2O3 transparent ceramics by sintering aid combinations

Uranium doped Y2O3 transparent ceramics with ZrO2 and La2O3 as sintering aids, Ca2+ as charge compensator were successfully fabricated via a vacuum solid-state reactive sintering for the first time. The obtained ceramic showed a pure cubic Y2O3 phase structure and homogeneous microstructure with the average grain size of 20 μm. The in-line transmittance of the obtained U: Y2O3 reached 78% at 1300 nm. And the cut-off wavelength shifted from 250 nm to 520 nm, which was ascribed to the absorption of uranate ions. XPS and photoluminescence study confirmed uranium stabilizes as +6 oxidation state in the form of UO66−. The decay curve shows two lifetime values indicating that uranate ions are not homogeneously distributed in Y2O3 and it has two different environments due to its stabilization at both C2 and S6 sites. The lifetime population analysis shows that most UO66− ions were located at the non-centrosymmetric C2 site. The experimental results are helpful in designing Y2O3 based optoelectronic material as well exploring it for uranium studies. •U: Y2O3 transparent ceramics with transmittance of 78% at 1300 nm were fabricated for the first time.•The cut-off wavelength shifted from 250 nm to 520 nm due to the absorption of uranate ions.•XPS and photoluminescence study confirmed uranium stabilizes as +6 oxidation state in the form of UO66−.•Lifetime data shows UO66− is getting stabilized in two different environments in Y2O3.•Higher population of UO66− located at the non-centrosymmetric C2 sites.