Abstract
The field dependence of the hyperfine interaction of 161Dy in Au has been studied in external magnetic fields up to 3.21 T by means of Mossbauer spectroscopy. 161Dy was introduced into a single crystal of Au by means of low-temperature ion implantation. From the measurements the authors determine the parameters of the cubic crystalline electric field acting on the Dy nuclei: A4(r4)=-25.4-2.5+1.2K and A6(r6)=+1.34-1.22+0.50K, in agreement with EPR results. The ground state is a Gamma 8(1) quartet separated from a Gamma 8(2) excited quartet by Delta =10.8-0.6+0.9K.