Electric field gradients produced by impurity atoms in a cubic Ag lattice

In this contribution results are presented of TDPAC measurements of electric quadrupole interactions in a cubic Ag host with Cu and Sn impurities. The results for Cu and Sn impurities at the same concentration show that there is an effect due to valence difference Z between solute and solvent. The attenuation is stronger in the SnAg system with Z=3 than in CuAg with Z=0. The general shape of the G2(t) curves reflects the distribution of EFG's originated from the random distribution of impurity atoms in the host. Nuclei at various distances from surrounding solute atoms are subjected to different EFG's. This result is consistent with long-range oscillations of conduction electron density due to the screening charge around the solute. (Auth.)