Electric quadrupole interactions and the λ-α phase transition in Ce: the role of conduction electrons
Department of Physics, University of Antwerp, UIA, 2610 Antwerpen, Belgium
Revised: 2 May 2000
Published online: 15 September 2000
We present a theoretical model of the "isostructural" γ-α phase transition in Ce which is based on quadrupolar interactions due to coupled charge density fluctuations of 4f electrons and of conduction electrons. The latter are treated in tight-binding approximation. The γ-α transition is described as an orientational ordering of quadrupolar electronic densities in a structure. The quadrupolar order of the conduction electron densities is complementary to the quadrupolar order of 4f electron densities. The inclusion of conduction electrons leads to an increase of the lattice contraction at the γ-α transition in comparison to the sole effect of 4f electrons. We calculate the Bragg scattering law and suggest synchrotron radiation experiments in order to check the structure.
PACS: 71.10.-w – Theories and models of many electron systems / 71.27.+a – Strongly correlated electron systems; heavy fermions / 71.45.-d – Collective effects
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2000