Fast luminescence of HfO2–Yb2O3 and ZrO2–Yb2O3 solid solutions

For the first time in HfO2–Yb2O3 and ZrO2–Yb2O3 solid solutions fast luminescence with a characteristic time of ∼20 ns was observed, it was attributed to the charge transfer process involving the states of Yb3+ ion and adjacent oxygen in as-grown crystals. The maxima of the luminescence bands were at 280 and 430 nm. Luminescence excitation spectra and decay kinetics are presented. Annealing of the samples for 12 h at 1000°C in air resulted in a considerable change in the luminescence properties of HfO2–Yb2O3 crystals: a new band with enhanced yield peaking at 360 nm at room temperature and 400 nm at 6 K appeared with a characteristic decay time of ∼25 ns, which was attributed to Yb2+.