TY - JOUR

T1 - Site-selective time resolved laser fluorescence spectroscopy of Eu and Cm doped LaPO 4

AU - Holliday, Kiel S.

AU - Babelot, C.

AU - Walther, Clemens

AU - Neumeier, Stefan

AU - Bosbach, Dirk

AU - Stumpf, Thorsten

N1 - Funding information: Acknowledgment. The authors thank Sebastian Büchner for technical assistance with TRLFS measurements. This work was co-financed by the Helmholtz Gemeinschaft Deutscher Forschungszentren (HGF) by supporting the Helmholtz-Hochschul-Nachwuchsgruppe “Aufklärung geochemischer Reaktionsmechanismen an der Wasser/Mineralphasen Grenzfläche”. This work also was supported by the Ministerium für Innovation, Wissenschaft, Forschung und Technologie (MIWFT) des Landes Nordrhein-Westfalen; AZ: 323-005-0911-0129.

PY - 2011/11/2

Y1 - 2011/11/2

N2 - Samples of LaPO 4 doped with Eu 3+ or Cm 3+ were synthesized by a hydrothermal process which resulted in a solid solution at temperatures less than conventional processing. Time resolved laser fluorescence spectroscopy was used to probe the incorporated Eu 3+ or Cm 3+ in order to gain structural information on its local environment. This revealed that Eu 3+ and Cm 3+ incorporate on the La site as expected. The emission spectrum of Eu 3+ resolves the fully degenerate 5-fold splitting of the peaks in the F 2 transition due to the low symmetry of the site, confirming previous calculations. A minor site in the Eu 3+ doped sample is identified as coordinated with hydroxide contamination. Direct excitation of Cm 3+ doped samples show the presence of "satellite" species. Although these spectral features have been observed in Cm 3+ doped LuPO 4 and YPO 4, this is the first time that these satellites are resolved into their individual species. These are hypothesized to be due to a disturbance in the ideal structure which creates a break in the equivalence of the four lanthanum sites within a unit cell. The 4-fold ground state splitting of all species is identical, although slightly shifted, indicating similar environments. The fluorescence lifetimes were long (1.2ms for Cm and 3.6 ms for Eu) indicating an absence of water in the immediate coordination sphere due to the incorporation of the doping ion.

AB - Samples of LaPO 4 doped with Eu 3+ or Cm 3+ were synthesized by a hydrothermal process which resulted in a solid solution at temperatures less than conventional processing. Time resolved laser fluorescence spectroscopy was used to probe the incorporated Eu 3+ or Cm 3+ in order to gain structural information on its local environment. This revealed that Eu 3+ and Cm 3+ incorporate on the La site as expected. The emission spectrum of Eu 3+ resolves the fully degenerate 5-fold splitting of the peaks in the F 2 transition due to the low symmetry of the site, confirming previous calculations. A minor site in the Eu 3+ doped sample is identified as coordinated with hydroxide contamination. Direct excitation of Cm 3+ doped samples show the presence of "satellite" species. Although these spectral features have been observed in Cm 3+ doped LuPO 4 and YPO 4, this is the first time that these satellites are resolved into their individual species. These are hypothesized to be due to a disturbance in the ideal structure which creates a break in the equivalence of the four lanthanum sites within a unit cell. The 4-fold ground state splitting of all species is identical, although slightly shifted, indicating similar environments. The fluorescence lifetimes were long (1.2ms for Cm and 3.6 ms for Eu) indicating an absence of water in the immediate coordination sphere due to the incorporation of the doping ion.

KW - Curium

KW - Europium

KW - Lanthanum phosphate

KW - Site-selective

KW - TRLFS

UR - http://www.scopus.com/inward/record.url?scp=84857673916&partnerID=8YFLogxK

U2 - 10.1524/ract.2012.1900

DO - 10.1524/ract.2012.1900

M3 - Article

AN - SCOPUS:84857673916

VL - 100

SP - 189

EP - 195

JO - Radiochimica Acta

JF - Radiochimica Acta

SN - 0033-8230

IS - 3

ER -