Temperature Dependence of the Electric Field Gradient in Cubic Ag Metal Doped with Impurities

The electric quadrupole interactions produced by near-neighbor impurity atoms of Cu, Zn, In, Sn, and Au in a cubic Ag metal lattice are measured as a function of temperature by the time-differential perturbed angular correlation method. The obtained electric quadrupole frequencies $\omega$ can be reproduced by the relation $\omega \mathrm{}\left(T\right)=\omega \mathrm{}\left(0\right)(1-\alpha T^{\frac{3}{2}})$ with a strong dependence of the coefficient $\alpha$ on the impurity atom. The results are discussed in terms of recently proposed models to explain the $T^{\frac{3}{2}}$ dependence.