Characterization of the rare earth orthophosphates and Ce-doped LaPO{sub 4} by X-ray Absorption Spectroscopy
- Lawrence Berkeley Lab., CA (United States)
- Lawrence Livermore National Lab., CA (United States)
- Oak Ridge National Lab., TN (United States)
X-ray Absorption Spectroscopy (XAS) of the Rare Earth (RE) 3d levels yields sharp peaks near the edges as a result of strong, quasi-atomic 3d{sup 10}4f {yields} 3d{sup 9}4f{sup n+1} (M{sub 4,5}) transitions that contain a wealth of spectroscopic features. XAS is a useful technique for the characterization of 4f-occupancy, 4f-hybridization, and valence in RE-containing materials. The XAS measurements of the single crystal RE-orthophosphates, as well as a range of Cedoped ({approx}1--30%) LaPO{sub 4} hosts were performed at the 3d edge in the total electron yield mode at beamline 8-2 at the Stanford Synchrotron Radiation Laboratory (SSRL). The XAS spectra of the RE ions in the orthophosphate matrix generally resemble that of the corresponding RE metal and emphasize the major contribution of the trivalent state to the electronic transitions occurring at the 3d edge. There is no energy shift of the La and Ce absorption peaks with Ce doping and furthermore, no additional transitions are observed in either spectral region. However, accompanying the Ce doping there is a significant narrowing of the La absorption peak full width half maximum that contrasts to the Ce features that exhibit no contraction. The La and Ce spectra indicate that the Ce-doping of LaPO{sub 4} is purely substitutional.
- Research Organization:
- Oak Ridge National Lab., TN (United States); Lawrence Berkeley Lab., CA (United States); Lawrence Livermore National Lab., CA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC05-84OR21400; AC03-76SF00098; W-7405-ENG-48
- OSTI ID:
- 10120486
- Report Number(s):
- CONF-931108-73; ON: DE94006313
- Resource Relation:
- Conference: Fall meeting of the Materials Research Society (MRS),Boston, MA (United States),29 Nov - 3 Dec 1993; Other Information: PBD: [1993]
- Country of Publication:
- United States
- Language:
- English
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