NUCLEAR MAGNETIC-MOMENT OF THE FIRST EXCITED-STATE (I = 2(-238()) OF U)

The U-238 Mossbauer effect of UO2 has been investigated in the tempera ture range from 5.4 K to 280 K. Nuclear Zeeman splitting of the U-238 nucleus in antiferromagnetic UO2 at 5.4 K is 59.1 +/- 3.9 mm s(-1) and corresponds to the value of 252.3 +/- 0.5 T obtained by the U-235 pul sed NMR technique. The nuclear magnetic moment of the first excited st ate (I = 2(+)) of U-238 has been determined to be 0.254 +/- 0.0151 mu( N). The conversion factor of 4.27 +/- 0.28 T/mm s(-1) enables us to U- 238 Mossbauer spectroscopy. determine the hyperfine magnetic field at the U-238 nucleus using The temperature dependence of the recoil-free fraction of the U-238 Mossbauer effect in UO2 has been discussed.