Crystallochemistry of uranium oxides

Almost 40 compounds of uranium and oxygen exist due to the fact that uranium has wide range of valencies (III to VI). These oxides form crystals with various O/U composition ratios and with different crystallographic structures; from among them uranium dioxide (UO2) is commonly used nuclear fuel. Studies of UO2, and also of higher oxides created by introducing oxygen to the UO2 structure, are carried out not only in relation with behavior of this oxide in the reactor conditions, but also due to the environmental problems concerned with the spent fuel storage. It is planned that Ph.D. student will work on crystallochemical problems of two oxides: U4O9 and U3O7, which are crystallographic derivatives of UO2. Series of experiments are to be performed with the (powder and single crystal) X-ray crystallography, ion-implantation technique, and ion-beam analysis (backscattering spectrometry with channeling). Theoretical part of the work should include calculations of crystal structure energies in relation with formation of oxygen clusters in U4O9 and U3O7. Due to this part of the work, it is expected that the student has high skills in programming (Delphi and/or C).

Bibligraphy:

  1. L. Nowicki, A.Turos, C.Choffel, F.Garrido, L.Thomé, J. Gaca, M. Wojcik, and Hj.Matzke, Quasiepitaxial growth of a monoclinic phase on UO2 single crystals upon leaching in H2O, Phys. Rev. B 56 (1997), 534-42
  2. L.Nowicki, F.Garrido, A.Turos and L.Thome, Polytypic arrangements of cuboctahedral oxygen clusters in U3O7, J.Physics and Chem. of Solids 61 (2000) 1789-1804
More information: Professor Andrzej Turos
SINS Nuclear Reaction Department
00-681 Warszawa, Ho¿a 69
tel. (++4822) 5532129
turos@fuw.edu.pl