Pulsed-beam study ofCd111nuclear quadrupole interaction with recoil-induced lattice defects in cubic palladium

The quadrupole interaction of excited ${}_{}{}^{111}{}_{}{}^{}\mathrm{Cd}$ nuclei with electric field gradients due to lattice defects in fcc palladium has been studied by the technique of time-differential observation of perturbed angular distribution of $\gamma$ rays. The lattice defects were induced by the recoiling ions following the nuclear reaction ${}_{}{}^{108}{}_{}{}^{}\mathrm{Pd}(\alpha ,n){}_{}{}^{111}{}_{}{}^{}\mathrm{Cd}$. A sharp frequency of 87(2) MHz is assigned to trapped interstitials. A broad temperature-dependent frequency distribution arising from various other lattice defects was found. A migration energy of 0.10(2) eV for free interstitials is deduced.