Study of Rare-Earth Ions Implanted into Copper, Aluminum, Silver, and Rhodium

Abstract

Various even-even isotopes of Er, Dy, and Yb have been Coulomb excited to their first $2^{+}$ states and implanted into metallic foils of Cu, Al, Ag, and Rh. The attenuation of the subsequent $\gamma$-ray angular distribution was measured as a function of temperature and interpreted in terms of a predominant time-dependent magnetic interaction with small admixtures of static and time-dependent electric interactions. Correlation times have been extracted and quantitively compared to the electronic relaxation times ($T_2$) obtained from electron-paramagnetic-resonance measurements of the same impurity-host systems. Comparisons are favorable, provided crystalline-field effects are taken into account.