title: Optical properties of ammonium uranyl fluoride characterized by photoluminescence and photoacoustic spectroscopy.
abstract: PL and PAS studies were performed on uranyl compounds viz. uranium oxalate, uranium fluoride and ammonium uranyl fluoride. PL and PAS spectrum of ammonium uranyl fluoride is being reported for the first time. Ammonium uranyl fluoride is blue shifted with respect to uranyl fluoride, as a result of ammonium bonding. The vibronic separations were determined in the excited state and the ground state using excitation/PA spectra and emission spectra respectively. Fluorescence decay data could be fitted only with biexponential decay in all of these compounds indicating the presence of two different environments in these compounds. Low temperature luminescence leads to enhancement in emission intensity and lifetime value. The temperature dependence studies of average fluorescence lifetimes of ammonium uranyl are described in this paper. Based on this studies activation energy value for ammonium uranyl fluoride at which (3)∏ and (1)Σ potential surfaces will cross is calculated.
authors.affiliation: Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India. Electronic address: santoshg@barc.gov.in.
authors.forename: Santosh K
authors.initials: SK
authors.lastname: Gupta
authors.forename: A R
authors.initials: AR
authors.lastname: Dhobale
authors.forename: V
authors.initials: V
authors.lastname: Natarajan
authors.forename: S V
authors.initials: SV
authors.lastname: Godbole
mesh_terms: D064751:Ammonium Compounds / Q000737:chemistry*; D005459:Fluorides / Q000737:chemistry*; D008027:Light; D008163:Luminescent Measurements; D055095:Optics and Photonics; D061088:Photoacoustic Techniques; D013055:Spectrophotometry, Infrared; D013696:Temperature; D017974:Uranium Compounds / Q000737:chemistry*
chemical_list: D064751:Ammonium Compounds; D017974:Uranium Compounds; C036637:uranyl fluoride; D005459:Fluorides
keywords: Ammonium uranyl fluoride; Life time; Photoacoustic; Photoluminescence; Uranium