Using time-differential perturbed angular correlation spectroscopy we have measured the electric field gradient ͑EFG͒ at 111 Cd probe nuclei in solid Ce in a pressure range up to 8 GPa. Covering various allotropic phases of Ce, we find that the value of the EFG in the cubic ␣ phase is almost four times larger than in the cubic ␥ phase and close to values in the noncubic phases ␣Ј and ␣Љ. These results together with the differences in time modulation of the spectra are interpreted as evidence for quadrupolar electronic charge-density ordering and symmetry lowering at the ␥ → ␣ transition while the lattice remains face-centered cubic.

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Radioactive 111In was introduced into the Laves phases YMn2, GdFe2 and YbFe2 synthesized under pressure of 8 GPa, and the hyperfine interaction of the daughter 111Cd was measured by the perturbed angular correlation method. In the obtained hexagonal (C14) phase YMn2 111In is substituted for Mn, predominantly at h‐sites, experiencing there an electric quadrupole interaction with νQ = 32.0(5) MHz and η = 0.51(5) at 300 K. In GdFe2 and YbFe2 (cubic C15) most of the 111In–111Cd probes (≈︂80%) substituted mainly for the rare earth atoms and experienced a magnetic hyperfine field |Bhf| = 2.92(4) T and 3.32(7) T, respectively, at 300 K. The results are discussed together with the published data for the normal cubic YMn2, and for LuFe2 and ZrFe2.

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