Research output: Contribution to journal › Article › peer-review
Effect of the chemical state of uranium atom on the energy of spin-orbital splitting of its inner orbitals. / Batrakov, Yuri F.; Krivitsky, Andrey G.; Pospelov, Oleg V.; Puchkova, Elena V.
In: Radiochimica Acta, Vol. 92, No. 2, 02.04.2004, p. 73-80.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Effect of the chemical state of uranium atom on the energy of spin-orbital splitting of its inner orbitals
AU - Batrakov, Yuri F.
AU - Krivitsky, Andrey G.
AU - Pospelov, Oleg V.
AU - Puchkova, Elena V.
PY - 2004/4/2
Y1 - 2004/4/2
N2 - Chemical shifts (ChSh) of nine emission lines of the uranium L-series in uranium oxides UO2+x (x = 0-1) with respect to UO2 were studied by using a precise crystal-diffraction X-ray spectrometer. ChSh of Lα1, α2 uranium and thorium lines in solid solutions yUO2 · (1-y)ThO2 (y = 0÷1) were measured with respect to UO2 and ThO2, respectively. The changes in energy of spin-orbital splitting (SOS) - Δδnl ± of inner nl-orbitals of the uranium atom were calculated from the data of ChSh of spin-doublet lines. For UO2+x oxides, a linear decrease in Δδnl± values with increasing degree of uranium oxidation was found. Sign inversion of Δδnl ± for uranium levels was found on passing to solid solutions. No change in the SOS energy of inner thorium levels was detected. The values of Δδnl± were found to correlate with the experimental values of the effective magnetic moment of uranium in oxides. On the basis of the comparison of experimental Δδnl± values with Dirac-Hartree-Fock atomic calculations, it was concluded that the observed variations in Δδnl± values are due to the redistribution of electron and spin density between the 5 f7/2- and 5 f5/2-levels of the fine structure of the uranium atom without changes in atomic charge state. On the basis of the hypothesis of intraatomic relativistic U 5 f7/2 ↔ U 5 f5/2 transition, a model of paramagnetic moment formation on the uranium atom in uranium dioxide was proposed.
AB - Chemical shifts (ChSh) of nine emission lines of the uranium L-series in uranium oxides UO2+x (x = 0-1) with respect to UO2 were studied by using a precise crystal-diffraction X-ray spectrometer. ChSh of Lα1, α2 uranium and thorium lines in solid solutions yUO2 · (1-y)ThO2 (y = 0÷1) were measured with respect to UO2 and ThO2, respectively. The changes in energy of spin-orbital splitting (SOS) - Δδnl ± of inner nl-orbitals of the uranium atom were calculated from the data of ChSh of spin-doublet lines. For UO2+x oxides, a linear decrease in Δδnl± values with increasing degree of uranium oxidation was found. Sign inversion of Δδnl ± for uranium levels was found on passing to solid solutions. No change in the SOS energy of inner thorium levels was detected. The values of Δδnl± were found to correlate with the experimental values of the effective magnetic moment of uranium in oxides. On the basis of the comparison of experimental Δδnl± values with Dirac-Hartree-Fock atomic calculations, it was concluded that the observed variations in Δδnl± values are due to the redistribution of electron and spin density between the 5 f7/2- and 5 f5/2-levels of the fine structure of the uranium atom without changes in atomic charge state. On the basis of the hypothesis of intraatomic relativistic U 5 f7/2 ↔ U 5 f5/2 transition, a model of paramagnetic moment formation on the uranium atom in uranium dioxide was proposed.
KW - Chemical bond
KW - Chemical shift
KW - Relativistic effects
KW - Uranium
KW - Uranium compound
KW - X-ray emission
UR - http://www.scopus.com/inward/record.url?scp=1642348469&partnerID=8YFLogxK
U2 - 10.1524/ract.92.2.73.27465
DO - 10.1524/ract.92.2.73.27465
M3 - Article
AN - SCOPUS:1642348469
VL - 92
SP - 73
EP - 80
JO - Radiochimica Acta
JF - Radiochimica Acta
SN - 0033-8230
IS - 2
ER -
ID: 36901047