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Optical spectroscopy of f-element compounds

Description: It is noted that the energies and intensities of transitions observed in the optical spectra of lanthanide (Ln) and actinide (An) compounds can typically be measured with a high degree of accuracy. The observed transitions can then be directly represented as upper state energy levels where the structure is induced by the environment. A discussion is presented of the systematic theoretical interpretation of these transitions both in terms of energy level structure and transition probability. Par… more
Date: January 1, 1978
Creator: Carnall, W. T.
Partner: UNT Libraries Government Documents Department
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Systematic view of optical absorption spectra in the actinide series

Description: In recent years sufficient new spectra of actinides in their numerous valence states have been measured to encourage a broader scale analysis effort than was attempted in the past. Theoretical modelling in terms of effective operators has also undergone development. Well established electronic structure parameters for the trivalent actinides are being used as a basis for estimating parameters in other valence states and relationships to atomic spectra are being extended. Recent contributions to… more
Date: January 1, 1985
Creator: Carnall, W. T.
Partner: UNT Libraries Government Documents Department
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Crystal and solution spectroscopy of einsteinium

Description: Work on spectra and electronic structure of Es/sup 3 +/ is reviewed. Laser-excited fluorescence spectroscopy was used to study Es/sup 3 +/-doped LaCl/sub 3/ crystals; fluorescence transitions and lifetimes were determined. A complete ground-state splitting diagram was also constructed for Es/sup 3 +/: LaCl/sub 3/. Some data on excited states of Fm/sup 3 +/ are also included. 12 figures. (DLC)
Date: January 1, 1978
Creator: Carnall, W. T.
Partner: UNT Libraries Government Documents Department
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Spectroscopic studies of the transplutonium elements

Description: The challenging opportunity to develop insights into both atomic structure and the effects of bonding in compounds makes the study of actinide spectroscopy a particularly fruitful and exciting area of scientific endeavor. It is also the interpretation of f-element spectra that has stimulated the development of the most sophisticated theoretical modeling attempted for any elements in the periodic table. The unique nature of the spectra and the wealth of fine detail revealed make possible sensiti… more
Date: January 1, 1983
Creator: Carnall, W. T. & Conway, J. G.
Partner: UNT Libraries Government Documents Department
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A systematic analysis of the spectra of trivalent actinide chlorides in D sub 3h site symmetry

Description: The optical spectra of actinide ions in the compound AnCl{sub 3} and doped into single crystal LaCl{sub 3} were interpreted in terms of transitions within 5f{sup N} configurations. Energy-level calculations were carried out using an effective operator Hamiltonian, the parameters of which were determined by fitting experimental data. Atomic and crystal-field matrices were diagonalized simultaneously assuming an approximate D{sub 3h} site symmetry. The spectroscopic data were taken from the liter… more
Date: November 1, 1989
Creator: Carnall, W. T.
Partner: UNT Libraries Government Documents Department
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Energy Level Structure and Transition Probabilities in the Spectra of the Trivalent Lanthanides in LaF₃

Description: Two types of correlations with experimental results are reported. For even-f-electron systems, a center of gravity was computed based on the energies of the observed states, and calculated optimized sets of atomic energy level parameters. For odd-electron systems complete crystal field calculations were performed in which parameters of both the atomic and crystal-field parts of the interaction were adjusted to experimental data. The result is a set of eigenvectors for all the ionic states in ea… more
Date: 1978
Creator: Carnall, W. T.; Crosswhite, H. M. & Crosswhite, H. M.
Partner: UNT Libraries Government Documents Department
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A systematic analysis of the spectra of the lanthanides doped into single crystal LaF/sub 3/

Description: The optical spectra of the lanthanides doped into single crystal LaF/sub 3/ have been interpreted in terms of transitions within 4f/sup N/ configurations. Energy-level calculations were based on a simultaneous diagonalization of the free-ion and crystal-field matrices using an approximate model with C/sub 2v/ site symmetry instead of the actual C/sub 2/ symmetry. Excellent correlations between experimental transition energies and the computed level structures were obtained; predicted levels are… more
Date: February 1, 1988
Creator: Carnall, W. T.; Goodman, G. L.; Rajnak, K. & Rana, R. S.
Partner: UNT Libraries Government Documents Department
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Electronic structure of uranyl compounds: an XPS study

Description: X-ray photoemission spectroscopy (XPS) measurements are reported for a series of uranyl compounds in which the primary uranium--oxygen (U--O/sub I/) separation varies substantially. Crystal field splittings of the U 6p$sub 3$/ $sub 2$ core electron energy levels were observed. These splittings are explained with the point charge crystal field model when both first and second near uranium neighbors are considered. The systematics of charge migration (observed by monitoring electron core level sh… more
Date: January 1, 1975
Creator: Veal, B. W.; Lam, D. J.; Hoekstra, H. R. & Carnall, W. T.
Partner: UNT Libraries Government Documents Department
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Measurement and interpretation of plutonium spectra

Description: The atomic spectroscopic data available for plutonium are among the rickest of any in the periodic system. They include high-resolution grating and Fourier-transform spectra as well as extensive Zeeman and isotope-shift studies. We summarize the present status of the term analysis and cite the configurations that have been identified. A least-squares adjustment of a parametric Hamiltonian for configurations of both Pu I and Pu II has shown that almost all of the expected low levels are now know… more
Date: January 1, 1982
Creator: Blaise, J.; Fred, M. S.; Carnall, W. T.; Crosswhite, H. M. & Crosswhite, H.
Partner: UNT Libraries Government Documents Department
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Spectroscopic properties of the f-elements in compounds and solutions. [79 references]

Description: In this systematic examination of some of the spectroscopic properties of the f-elements we deal with both the trivalent lanthanides and actinides. We summarize the present status of our energy level calculations in single crystal matrices and in aqueous solution, and compare the predicted crystal-field structure in certain low-symmetry sites with that observed. Some interesting new structural insights are thereby gained. The state eigenvectors from these calculations are then used in part in r… more
Date: January 1, 1982
Creator: Carnall, W. T.; Beitz, J. V.; Crosswhite, H.; Rajnak, K. & Mann, J. B.
Partner: UNT Libraries Government Documents Department
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XPS studies of actinide materials. [X-ray photoemission spectroscopy, review]

Description: Applications of x-ray photoemission spectroscopy (XPS) to the study of actinide materials are reviewed. Examples discussed here include the band structures of thorium and uranium metal, the multiplet structure associated with the 5f electron states in oxides of the transuranium elements, the test for temporal configurations in NpO/sub 2/, crystal field splitting of the U 6p/sub /sup 3///sub 2// level in a series of uranyl compounds, mixed oxidation states in Cf/sub 7/O/sub 12/, and a test for t… more
Date: September 13, 1976
Creator: Veal, B. W.; Lam, D. J.; Hoekstra, H. R.; Diamond, H. & Carnall, W. T.
Partner: UNT Libraries Government Documents Department
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Energy Level Structure and Transition Probabilities in the Spectra of the Trivalent Lanthanides in Laf/Sub 3/. [Tables, Diagrams]

Description: Two types of correlations with experimental results are reported. For even-f-electron systems, a center of gravity was computed based on the energies of the observed states, and calculated optimized sets of atomic energy level parameters. For odd-electron systems complete crystal field calculations were performed in which parameters of both the atomic and crystal-field parts of the interaction were adjusted to experimental data. The result is a set of eigenvectors for all the ionic states in ea… more
Date: January 1, 1978
Creator: Carnall, W. T.; Crosswhite, H. & Crosswhite, H. M.
Partner: UNT Libraries Government Documents Department
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Photoelectron, nuclear gamma-ray and infrared absorption spectroscopic studies of neptunium in sodium silicate glass

Description: The valence state of neptunium ions in sodium silicate glasses prepared under reducing and oxidizing conditions has been investigated by the x-ray photoelectron, Moessbauer and optical absorption spectroscopic techniques. Results indicate that the Np ions are tetravalent in glasses prepared under reducing conditions and pentavalent in glasses prepared under oxidizing conditions.
Date: April 1, 1986
Creator: Veal, B. W.; Carnall, W. T.; Dunlap, B. D.; Mitchell, A. W. & Lam, D. J.
Partner: UNT Libraries Government Documents Department
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TbCl/sub 3/--AlCl/sub 3/ vapors: characteristics of a potential new high energy gas phase laser medium

Description: The absorption and fluorescence spectra, excited state lifetimes and ion densities of TbCl/sub 3/-AlCl/sub 3/ vapors have been measured. The temporal evolution of /sup 5/D/sub 4/ fluorescence is analyzed.
Date: January 1, 1978
Creator: Caird, J. A.; Hessler, J. P.; Carnall, W. T.; Williams, C. W. & Lance-Gomez, T.
Partner: UNT Libraries Government Documents Department
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Vapor phase spectroscopy of complex lanthanide halide--aluminum halide molecular species

Description: The absorption spectrum of ErCl/sub 3/ (AlCl/sub 3/)/sub x/ vapor complex was measured and analyzed using the Judd-Ofelt theory. Structural correlations in other AlCl/sub 3/ vapor complexes and radiation emission are discussed. Fluorescence of TbCl/sub 3/ (AlCl/sub 3/)/sub x/ vapor complex and in the NdCl/sub 3/ (AlCl/sub 3/)/sub x/ system were studied. (DLC)
Date: January 1, 1977
Creator: Carnall, W T; Hessler, J P; Williams, C W & Hoekstra, H R
Partner: UNT Libraries Government Documents Department
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Optical Spectra and Electronic Structure of Actinide Ions in Compounds and in Solution

Description: This report provides a summary of theoretical and experimental studies of actinide spectra in condensed phases. Much of the work was accomplished at Argonne National Laboratory, but references to related investigations by others are included. Spectroscopic studies of the trivlent actinides are emphasized, as is the use of energy level parameters, evaluated from experimental data, to investigate systematic trends in electronic structure and other properties. Some reference is made to correlation… more
Date: August 1985
Creator: Carnall, W. T. & Crosswhite, H. M.
Partner: UNT Libraries Government Documents Department
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Vibronic interaction and crystal structure distortion in Cm sup 4+ :CeF sub 4

Description: We have applied selective excitation to unravel the complex 5f state spectra of Cm{sup 4+} in CeF{sub 4} which arises from multiple metal ion sites and vibronic interactions. An unusual laser-induced site distortion on one of the two ion-sites has been studied. Distinct spectral lines of the distorted ion site were detected. The site distortion was found to be stable below 45 K and reverted, via a thermally activated process, at higher temperatures. Below 45 K, persistent spectral holes were bu… more
Date: January 1, 1990
Creator: Liu, G. K.; Beitz, J. V. & Carnall, W. T.
Partner: UNT Libraries Government Documents Department
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New approaches to the study of lanthanide/actinide chloride: aluminum chloride vapor phase complexes

Description: The spectrophotometric technique for vapor density measurements of complexed metal ions has been reformulated to account for temperature dependent effects and multi-species systems. Analysis of vapor pressure information indicates that the NdCl/sub 3/--AlCl/sub 3/ and HoCl/sub 3/--AlCl/sub 3/ systems are adequately explained by the existence of three vapor species. The two higher molecular weight complexes LnAl/sub 4/Cl/sub 15/ and LnAl/sub 3/Cl/sub 12/ were first proposed by Oeye and Gruen. Th… more
Date: January 1, 1979
Creator: Peterson, E. J.; Caird, J. A.; Carnall, W. T.; Hessler, J. P.; Hoekstra, H. R. & Williams, C. W.
Partner: UNT Libraries Government Documents Department
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Fluorescence and excitation spectra of Bk/sup 3 +/, Cf/sup 3 +/, and Es/sup 3 +/ ions in single crystals of LaCl/sub 3/

Description: Self-fluorescence measurements have two disadvantages: the excitation and relaxation mechanisms are not understood, therefore the fluorescing level is difficult to assign, and fluorescence from daughter ions is also present. To obtain the 5f/sup n/ ion energy level structure with the highest possible precision, ions dilutely substituted into single crystal host lattices are needed. Concentrated systems such as EsBr/sub 3/ will exhibit line broadening due to ion-ion interactions. This limits the… more
Date: January 1, 1977
Creator: Hessler, J. P.; Caird, J. A.; Carnall, W.T.; Crosswhite, H. M.; Sjoblom, R. K. & Wagner, Jr., F.
Partner: UNT Libraries Government Documents Department
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A Systematic Analysis of the Spectra of Trivalent Actinide Chlorides in D3h Site Symmetry

Description: The optical spectra of actinide ions in the compound AnCl₃ and doped into single crystal LaCl₃ were interpreted in terms of transitions within 5f{sup N} configurations. Energy-level calculations were carried out using an effective operator Hamiltonian, the parameters of which were determined by fitting experimental data. Atomic and crystal-field matrices were diagonalized simultaneously assuming an approximate D{sub 3h} site symmetry. The spectroscopic data were taken from the literature but in… more
Date: November 1989
Creator: Carnall, W. T.
Partner: UNT Libraries Government Documents Department
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