Mossbauer-effect study of europium in glass

Mossbauer spectra have been obtained for Eu-151 in some silicate and phosphate glasses. In the silicate glasses Eu3+ behaves very much as it does in Eu2O3. The isomer shift relative to Eu2O3 is similar to 0.1 mm/sec. Some broadening of the line can be attributed to unresolved quadrupole splitting and to disorder in the glass structure. The recoilless fraction is 0.33. Measurements made at elevated temperatures indicate a complicated dependence of isomer shift on temperature cycling. In europium phosphate glass the isomer shift is similar to-0.3 mm/sec, and the linewidth is approximately the same as for the silicate glasses.