Sample records for cerium-alpha

  1. Nuclear {sup 111}Cd probes detect a hidden symmetry change at the {gamma} {sup {yields} {alpha}} transition in cerium considered isostructural for 60 years

    SciTech Connect

    Tsvyashchenko, A. V.; Nikolaev, A. V.; Velichkov, A. I.; Salamatin, A. V.; Fomicheva, L. N.; Ryasny, G. K.; Sorokin, A. A.; Kochetov, O. I.; Budzynski, M.


    We use the time-differential perturbed angular correlation technique to study nuclear electric quadrupole hyperfine interactions of probe {sup 111}Cd nuclei in cerium lattice sites at room temperature under pressures up to 8 GPa. We have found that the well known {gamma} {sup {yields} {alpha}} phase transition in cerium is not isostructural. In {alpha}-Ce, the probe {sup 111}Cd nuclei reveal a quadrupole electron charge density component that is absent in {gamma}-Ce. The hidden spacial structure of electronic quadrupoles in {alpha}-Ce is triple-q antiferroquadrupolar, as was suggested in [14]. We relate our findings to the current understanding of the {gamma} {sup {yields} {alpha}} phase transition and also report on nuclear quadrupole interactions in other high-pressure phases of cerium: {alpha}'' (C2/m space symmetry) and {alpha}' ({alpha}-U structure).