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The K-absorption edge of vanadium in some vanadium compounds
Vol. 28, No.4
ABSTRACTS OF ARTICLES TO BE PUBUSHED IN J. PHYS. CHEM. SOUDS
Using a two parameter model pseudopotential, in conjuction with the recent improved self-consistent dielectric function of Vashishta and Singwi, we have studied the phonon dispersion relations of cadmium which crystallizes in h.c.p. structure with maximum anisotropy (c/a = 1.89). 11.
ELECTRONIC AND STRUCTURAL PROPERTIES OF SOME TERNARY NEPTUNIUM 7NpMoSsBAUER (VII) OXIDES FROM ~ SPECTROSCOPY J .M. Friedt and G.K. Shenoy, Laboratoire de Chimie Nucléaire, Centre de Recherches Nucléaires, 67037 Strasbourg Cedex, France and Argonne National Laboratory, Argonne, ILL 60439, U.S.A.; and M. Pages, Laboratoire Curie, Institut du Radium, 75231 Paris Cedex
in
V204, V205, VF~,V3S3 and VSi2. The fine structures below the edge (the white line) as well as the fine structures above the edge of some of the studied compounds were observed. The molecular orbital theory is used to interpret the chemical energy shift of the edge and the observed phenomena. The electron configuration of the valence shells of the metal ion in some vanadium cornpounds were discussed and relate to the measured chemical shifts.byEffective charge the metal ion is also deduced comparing the of measured chemical shifts with SCF results. Received 15 May 1978 Revised 5 August 1978
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05, France. The 60keV Mossbauer resonanceof Np has been measured in some complex oxides of heptavalent neptunium. The nature of bonding and the molecular symmetry are discussed on the basis of the isomer shift and quadrupole constant data. The molecular character of the coupling compounds is evidenced by the low Debye temperatures and the strong bond covalency. The quadrupole coupling constant is temperature indepen. dent; this reveals the absence of any non-bonding states offelectrons. Received 22 May 1978
12.
THE KABSORPTION EDGE OF VANADIUM IN SOME VANADIUM COMPOUNDS C.N. Chang, S.I. Salem and T.J. Nash, Depart. ment of Physics-Astronomy, California State University-Long Beach, Long Beach, CA 90840, U.S.A.
The K-absorption edge of vanadium was studied in the following compounds: VB2, VC, VN, VO, V2O3,
13.
A MöSSBAUER STUDY OF CaBaFe
4O8 N. Raw and R. Jagannathan, School of Chemistry, University of Hyderabad, Hyderabad 500 001 hid~ la. The alkaline—earth monoferrites have been studied in much less detail than2~Fe~O~. the spinel-type double oxides of The spinel structures the obtained general formula Mdivalent ions are small. When the are when the size of the divalent ion increases, as in the case of the alkaline earth ferrites, many variations in the structure occur. For instance CaFe 2O4 and BaFe2O4 crystallise with the spin-free trivalent iron in octahedral and tetrahedral coordination respectively. These two monoferrites give rise to a new intermediate phase with the composition CaBaFe4O8 [1].A Mossbauer study of these systems can provide valuable additional information, as the technique is sensitive to variations in the symmetry around the iron site and the magnetic interactions present. Detailed Mössbauer studies on the systems CaFe2O4 and BaFe2O4 have been reported by earlier workers. .
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Received 8 May 1978 Revised 5 August 1978
ABSTRACTS OF ARTICLES TO BE PUBUSHED IN J. PHYS. CHEM. SOUDS
Using a two parameter model pseudopotential, in conjuction with the recent improved self-consistent dielectric function of Vashishta and Singwi, we have studied the phonon dispersion relations of cadmium which crystallizes in h.c.p. structure with maximum anisotropy (c/a = 1.89). 11.
ELECTRONIC AND STRUCTURAL PROPERTIES OF SOME TERNARY NEPTUNIUM 7NpMoSsBAUER (VII) OXIDES FROM ~ SPECTROSCOPY J .M. Friedt and G.K. Shenoy, Laboratoire de Chimie Nucléaire, Centre de Recherches Nucléaires, 67037 Strasbourg Cedex, France and Argonne National Laboratory, Argonne, ILL 60439, U.S.A.; and M. Pages, Laboratoire Curie, Institut du Radium, 75231 Paris Cedex
in
V204, V205, VF~,V3S3 and VSi2. The fine structures below the edge (the white line) as well as the fine structures above the edge of some of the studied compounds were observed. The molecular orbital theory is used to interpret the chemical energy shift of the edge and the observed phenomena. The electron configuration of the valence shells of the metal ion in some vanadium cornpounds were discussed and relate to the measured chemical shifts.byEffective charge the metal ion is also deduced comparing the of measured chemical shifts with SCF results. Received 15 May 1978 Revised 5 August 1978
—
05, France. The 60keV Mossbauer resonanceof Np has been measured in some complex oxides of heptavalent neptunium. The nature of bonding and the molecular symmetry are discussed on the basis of the isomer shift and quadrupole constant data. The molecular character of the coupling compounds is evidenced by the low Debye temperatures and the strong bond covalency. The quadrupole coupling constant is temperature indepen. dent; this reveals the absence of any non-bonding states offelectrons. Received 22 May 1978
12.
THE KABSORPTION EDGE OF VANADIUM IN SOME VANADIUM COMPOUNDS C.N. Chang, S.I. Salem and T.J. Nash, Depart. ment of Physics-Astronomy, California State University-Long Beach, Long Beach, CA 90840, U.S.A.
The K-absorption edge of vanadium was studied in the following compounds: VB2, VC, VN, VO, V2O3,
13.
A MöSSBAUER STUDY OF CaBaFe
4O8 N. Raw and R. Jagannathan, School of Chemistry, University of Hyderabad, Hyderabad 500 001 hid~ la. The alkaline—earth monoferrites have been studied in much less detail than2~Fe~O~. the spinel-type double oxides of The spinel structures the obtained general formula Mdivalent ions are small. When the are when the size of the divalent ion increases, as in the case of the alkaline earth ferrites, many variations in the structure occur. For instance CaFe 2O4 and BaFe2O4 crystallise with the spin-free trivalent iron in octahedral and tetrahedral coordination respectively. These two monoferrites give rise to a new intermediate phase with the composition CaBaFe4O8 [1].A Mossbauer study of these systems can provide valuable additional information, as the technique is sensitive to variations in the symmetry around the iron site and the magnetic interactions present. Detailed Mössbauer studies on the systems CaFe2O4 and BaFe2O4 have been reported by earlier workers. .
.
.
Received 8 May 1978 Revised 5 August 1978