161DY ISOMER SHIFTS IN DYSPROSIUM COMPOUNDS

Mössbauer absorption spectra were obtained for the 25.7 keV transitions of 161Dy in dysprosium metal and several compounds at room temperature. Isomer shifts relative to DyF3 are: Dy (metal), 3.05 mm sec-1; DyN, 0.85 mm sec-1; Dy2O3, 0.56 mm sec-1; DyH2.9, 0.55 mm sec-1; DyH2.1, 0.50 mm sec-1; DyF3. 1 2H2O, -0.04; and Dy2(SO43.8H2O, -0.46 mm sec-1. The relative isomer shifts of these compounds are attributed to varying degrees of covalency. The isomer shifts for the hydrides are compared to the predictions of the protonic and hydridic models for these compounds and appear to favor the hydridic model. © 1969.