Time Dependence of X-Ray Luminescence from Yttrium Oxide Nanoceramics

250–750 nm luminescence of yttrium oxide nanoceramics which are of great interest for several biomedicine applications was measured under the influence of X-ray radiation with up to 60 keV energy. The ceramics was produced from yttrium oxide nanopowder by sintering technique. The time dependence of the luminescent intensity at the 350 nm was investigated. It was shown that the decreasing intensity curve was good approximated by two-exponential function, which indicated the presence of fast and slow processes inducing the luminescence. The cyclic irradiation of the same sample showed that during the absence of irradiation an evident regeneration of the luminescent intensity occurred. The initial value of the intensity registered for each subsequent reirradiation significantly exceeded the final value of the intensity measured for the previous cycle. Wherein, the intensity decreased to a certain saturation value at the end of each cycle.