The electric quadrupole interaction of 111Cd in ZrZn2 and Zn in the samples prepared at 8 GPa

The perturbed angular correlation (PAC) measurements with the 111In-111Cd nuclear probe embedded into the lattice of the cubic (C15) Laves compound ZrZn2 showed that 111Cd nuclei experienced an axially symmetric electric quadrupole interaction with a frequency νQ = 132.4 MHz at room temperature. The samples were synthesized and doped with the probe at a pressure 8 GPa. The temperature dependence of νQ was shown to be linear: νQ(T) = 147(1 - 0.033 T) MHz. Since the value of νQ is very close to that known for 111Cd in the lattice of Zn, we have checked if it could be assigned to residual Zn metal in the sample. For the Zn sample melted and doped with 111In at 8 GPa we have obtained νQ = 117.3 MHz at 300 K and 127 MHz at 80 K - both values considerably lower than that for 111In doped Zn samples prepared at an ambient pressure. These data, and the fact that νQ(T) in Zn is known to follow the T3/2 law, allow to attribute the νQ value quoted above to 111Cd nuclei at the substitutional sites with tetrahedral symmetry in the Zn sublattice of ZrZn2.