Univ Sci & Technol China, State Key Lab Mat Chem & Applicat, Dept Phys, Grad Sch, Beijing 100039, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Beijing Synchrotron Radiat Facil, Beijing 100039, Peoples R China
; Chinese Acad Sci, Inst Semicond, Beijing 100083, Peoples R China
Eu ions doped SiO2 thin films, SiO2( Eu), were prepared by co-sputtering of SiO2 and Eu2O3 and Eu ion implantation into thermally grown SiO2 films. The Eu-L-3-edge X-ray absorption near edge structure (XANES) spectra of SiO2(Eu) films show a doublet absorption peak structure with energy difference of 7 eV, which indicates the conversion of Eu3+ to Eu2+ at high annealing temperature in N-2. The strong blue luminescence of SiO2(Eu) films prepared by ions implantation after films annealed above 1100 degreesC confirms the above argument.