skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: X-ray Absorption Spectroscopy of the Rare Earth orthophosphates

Abstract

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{sup n} {yields} 3d-{sup 9}4f{sup n+1} transitions and these transitions exhibit a wealth of spectroscopic features. The XAS measurements of single crystal REPO{sub 4} (RE = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er) at the 3d edge were performed in the total yield mode at beam line 8-2 at the Stanford Synchrotron Radiation Laboratory (SSRL). The XAS spectra of the RE ions in the orthophosphate matrix generally resemble the XAS of the corresponding RE metal. This is not unexpected and emphasizes the major contribution of the trivalent state to the electronic transitions at the RE 3d edges. These spectra unequivocally identify the transitions originating from well-characterized RE cores and correlate well with previous theoretical investigations.

Authors:
 [1];  [2]; ;  [3]
  1. Lawrence Berkeley Lab., CA (United States)
  2. Lawrence Livermore National Lab., CA (United States)
  3. Oak Ridge National Lab., TN (United States)
Publication Date:
Research Org.:
Lawrence Livermore National Lab., CA (United States); Lawrence Berkeley Lab., CA (United States); Oak Ridge National Lab., TN (United States)
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
10186804
Report Number(s):
UCRL-JC-114161; CONF-930405-47
ON: DE94001043; TRN: 93:025464
DOE Contract Number:
W-7405-ENG-48; AC03-76SF00098; AC05-84OR21400
Resource Type:
Conference
Resource Relation:
Conference: Spring meeting of the Materials Research Society,San Francisco, CA (United States),12-16 Apr 1993; Other Information: PBD: Jun 1993
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 36 MATERIALS SCIENCE; RARE EARTH COMPOUNDS; X-RAY SPECTRA; PHOSPHATES; ABSORPTION SPECTRA; ENERGY-LEVEL TRANSITIONS; 400201; 360606; CHEMICAL AND PHYSICOCHEMICAL PROPERTIES; PHYSICAL PROPERTIES

Citation Formats

Shuh, D.K., Terminello, L.J., Boatner, L.A., and Abraham, M.M. X-ray Absorption Spectroscopy of the Rare Earth orthophosphates. United States: N. p., 1993. Web.
Shuh, D.K., Terminello, L.J., Boatner, L.A., & Abraham, M.M. X-ray Absorption Spectroscopy of the Rare Earth orthophosphates. United States.
Shuh, D.K., Terminello, L.J., Boatner, L.A., and Abraham, M.M. Tue . "X-ray Absorption Spectroscopy of the Rare Earth orthophosphates". United States. doi:. https://www.osti.gov/servlets/purl/10186804.
@article{osti_10186804,
title = {X-ray Absorption Spectroscopy of the Rare Earth orthophosphates},
author = {Shuh, D.K. and Terminello, L.J. and Boatner, L.A. and Abraham, M.M.},
abstractNote = {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{sup n} {yields} 3d-{sup 9}4f{sup n+1} transitions and these transitions exhibit a wealth of spectroscopic features. The XAS measurements of single crystal REPO{sub 4} (RE = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er) at the 3d edge were performed in the total yield mode at beam line 8-2 at the Stanford Synchrotron Radiation Laboratory (SSRL). The XAS spectra of the RE ions in the orthophosphate matrix generally resemble the XAS of the corresponding RE metal. This is not unexpected and emphasizes the major contribution of the trivalent state to the electronic transitions at the RE 3d edges. These spectra unequivocally identify the transitions originating from well-characterized RE cores and correlate well with previous theoretical investigations.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Jun 01 00:00:00 EDT 1993},
month = {Tue Jun 01 00:00:00 EDT 1993}
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share:
  • 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 ofmore » 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.« less
  • Two types of solid-state lasers have served as key elements in the development of laser fusion: tunable lasers, such as Ti:sapphire, and lasers with discrete emissions based on neodymium. These lasers have been utilized for research, diagnostics, and as oscillators (i.e., ND:YLF) in the first stage. Crystalline phosphates were studied in depth many years ago for laser applications, but these crystals generally fell into disfavor when they could not be easily commercialized, A class of self activated materials, referred to as stoichiometric phosphates, were particularly interesting, since they could operate efficiently at high active ion concentrations without fluorescence quenching. Neodymiummore » pentaphosphate (NdP{sub 5}O{sub 14}) initiated this interest, but the potential for rare-earth orthophosphate (REOP) crystals was not seriously considered at that time. Extrinsic effects observed during some fundamental studies of REOP crystal properties, such as by electron paramagnetic resonance (EPR), may heighten the interest in using these latter materials for far-ranging laser applications, including laser fusion.« less
  • No abstract prepared.
  • X-ray photoelectron spectroscopy (XPS) and X-ray absorption near-edge spectroscopy (XANES) have been applied to examine the electronic structure of the rare-earth transition-metal oxyarsenides REFeAsO (RE=Ce, Pr, Nd, Sm, Gd) and CeNiAsO. Within the metal-arsenic layer [MAs], the bonding character is predominantly covalent and the As atoms are anionic, as implied by the small energy shifts in the M 2p and As 3d XPS spectra. Within the rare-earth-oxygen layer [REO], the bonding character is predominantly ionic, as implied by the similarity of the O 1s binding energies to those in highly ionic oxides. Substitution with a smaller RE element increases themore » O 1s binding energy, a result of an enhanced Madelung potential. The Ce 3d XPS and Ce L{sub 3}-edge XANES spectra have lineshapes and energies that confirm the presence of trivalent cerium in CeFeAsO and CeNiAsO. A population analysis of the valence band spectrum of CeNiAsO supports the formal charge assignment [Ce{sup 3+}O{sup 2-}][Ni{sup 2+}As{sup 3-}].« less
  • Soft x-ray absorption spectroscopy in the M-edge region is explored as a tool for studying 4f instabilities. The quasiatomic M/sub IV,V/ spectra, recorded by total-electron yield under UHV conditions, carry information on the initial-state 4f occupancy. For compounds of the heavy rare earths, even at high dilution (e.g., Tm/sub 0.05/Y/sub 0.95/Se), mean valences can be derived, which agree with those from lattice-constant systematics (e.g., for TmSe and Sm/sub 0.3/Y/sub 0.7/S). A moderate surface sensitivity allows the observation of surface-induced valence changes on EuPd/sub 3/, TmS, and SmAl/sub 2/. The M/sub IV,V/ spectra studied for 10 Ce compounds fall in twomore » categories: pure 3d/sup 9/4f/sup 1/ final-state multiplets for ..gamma..-like compounds, and additional peaks at about 5 eV higher energies for ..cap alpha..-like and intermediate systems. With increasing intensity of the satellites, which are assigned to 3d/sup 9/4f/sup 1/ final states, the 3d/sup 9/4f/sup 2/ multiplet structure gets washed out. An interpretation of the spectra with the recent Anderson-impurity theory of Gunnarsson and Schoenhammer leads to 4f occupancies greater than 0.7, even in extreme ..cap alpha..-like systems. In addition, M/sub III/-edge spectra exhibit one peak in ..gamma..-like and two peaks in ..cap alpha..-like and intermediate Ce systems, which are assigned to 3p/sup 5/4f/sup 1/ and 3p/sup 5/4f/sup 0/ final corestates. With increasing ..cap alpha..-like character, the 4f/sup 1/ peak is found to move to higher energies presumably due to a decrease in 4f screening with increasing 4f hybridization.« less