title: Vacuum ultraviolet excitation spectra of lanthanide-doped hexafluoroelpasolites.
abstract: Vacuum ultraviolet excitation spectra at ∼10 K have been recorded for [Formula: see text] transitions of Cs(2)NaYF(6):Ln(3+) (Ln = Nd, Sm, Eu, Tb, Ho, Er, Tm). In these high bandgap hosts the lanthanide ions occupy octahedral symmetry sites. The spectra comprise broad, structured bands and in most cases the individual vibronic structure is not resolved. Simulations of the relative intensities and band positions in the spectra have been made by using parameter values from previous studies and/or by employing values from similar systems or estimating trends across the lanthanide series, without data fitting or parameter adjustments. The agreement with experimental results is reasonable except where the luminescent state being monitored is not efficiently populated nonradiatively from the 4f(N-1)5d state, or where additional bands are present. The latter are readily assigned to charge transfer transitions or the near-excitonic band. Comparison of the spectra has been made with those of other high symmetry lanthanide ion systems.
authors.affiliation: Department of Biology and Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong SAR, People's Republic of China.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Tanner
authors.forename: Chang-Kui
authors.initials: CK
authors.lastname: Duan
authors.forename: Vladimir N
authors.initials: VN
authors.lastname: Makhov
authors.forename: Marco
authors.initials: M
authors.lastname: Kirm
authors.forename: Nicolas M
authors.initials: NM
authors.lastname: Khaidukov