Influence of CeO2 on scintillating properties of Tb3+-doped silicate glasses

A series of Tb3+-,Ce3+-doped,and Tb3+/Ce3+-codoped silicate glasses were synthesized by melt-quenching technique.Some properties of the investigated glasses were characterized by X-ray photoelectron spectroscopy(XPS),photoluminescence(PL),X-ray excited luminescence(XEL) and thermoluminescence(TL) spectra.The result of XPS revealed that both Ce3+ and Ce4+ ions coexisted in these silicate glasses,and energy transfer from Ce3+ to Tb3+ ions was observed under UV excitation.However,under X-ray excitation the XEL intensity of Tb3+ emission decreased dramatically upon introduction of CeO2 to the Tb3+-doped silicate glass,the higher the content of CeO2 was,the lower the intensity of Tb3+ emission was.A proposed TL mechanism was developed based the observed TL and XEL spectra.It was concluded that a cerium-related killer center formed in silicate glass with the introduction of CeO2,which competed the capture of electrons with Tb3+ luminescence center under X-ray excitation.