title: Synthesis and luminescence properties of Eu(III)-doped nanoporous silica spheres.
abstract: Europium (III) (Eu(3+))-doped nanoporous silica spheres were synthesized, and the states of Eu(3+) ions in the silica framework structure were investigated. The ordered nanopores were preserved with the doping at the Eu(3+) molar concentration to Si up to 10 mol%, and the O-Si-O and Si-OH groups in the structures were clearly rearranged with the doping, indicating the interaction of Eu(3+) with the O atoms. The significant morphological changes in the spheres were observed with the doping. The photoluminescence spectral shapes due to the transitions of (5)D(0)-(7)F(1) and (5)D(0)-(7)F(2) were indicative of the presence of the Eu(3+) in an environment of a low symmetry. It was found that the Eu(3+) was located inside the silica framework to electrostatically interact with the environmental O atoms, which would prevent the aggregation among Eu(3+) ions to show the efficient luminescence. Therefore, the interactions between the Eu(3+) ions and silica framework structures in the spheres were successfully clarified.
authors.affiliation: Graduate School of Science & Engineering, Tokyo Institute of Technology, Tokyo, Japan. tagaya.m.aa@m.titech.ac.jp
authors.forename: Motohiro
authors.initials: M
authors.lastname: Tagaya
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Ikoma
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Yoshioka
authors.forename: Satoshi
authors.initials: S
authors.lastname: Motozuka
authors.forename: Zhefeng
authors.initials: Z
authors.lastname: Xu
authors.forename: Fujio
authors.initials: F
authors.lastname: Minami
authors.forename: Junzo
authors.initials: J
authors.lastname: Tanaka
mesh_terms: D060326:Chemistry Techniques, Synthetic; D005063:Europium / Q000737:chemistry*; D049449:Luminescence; D049329:Nanostructures / Q000737:chemistry*; D010316:Particle Size; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D005063:Europium; D012822:Silicon Dioxide