title: Interconfigurational 5d → 4f luminescence of Ce3+ and Pr3+ in Ca9Lu(PO4)7.
abstract: Ca(9)Lu(PO(4))(7):Ce (3+) and Ca (9)Lu (PO (4))(7):Pr (3+) polycrystalline materials were synthesized by solid state reaction at high temperature. The materials were characterized by powder x-ray diffraction (XRPD). The luminescence spectroscopy and the excited state dynamics of these compounds were investigated upon excitation with UV/VUV synchrotron radiation. Both materials showed efficient and fast 5d-4f emission upon direct VUV excitation into the 5d levels but only Ca(9)Lu(PO(4))(7):Ce (3+) revealed luminescence upon excitation across the bandgap. The decay kinetics of the 5d-4f emission upon VUV intra-center excitation is characterized by a decay time of 29 ns for Ce (3+) and 17 ns for Pr (3+) with no significant build-up after the excitation pulse. For the both compounds, no significant temperature dependence of the 5d-4f emission lifetime was observed within the range 8-300 K.
authors.affiliation: Laboratory of Solid State Chemistry, Department of Biotechnology, University of Verona, and INSTM, UdR Verona, Verona, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Trevisani
authors.forename: K V
authors.initials: KV
authors.lastname: Ivanovskikh
authors.forename: F
authors.initials: F
authors.lastname: Piccinelli
authors.forename: A
authors.initials: A
authors.lastname: Speghini
authors.forename: M
authors.initials: M
authors.lastname: Bettinelli
mesh_terms: D017610:Calcium Compounds / Q000737:chemistry*; D002563:Cerium / Q000737:chemistry*; D004735:Energy Transfer; D008163:Luminescent Measurements; D008187:Lutetium / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry*; D011221:Praseodymium / Q000737:chemistry*; D017356:Synchrotrons
chemical_list: D017610:Calcium Compounds; D010710:Phosphates; D002563:Cerium; D008187:Lutetium; D011221:Praseodymium