PULSED NMR-STUDY OF PROTON MOTIONS IN URANIUM TRIOXIDE HYDRATES

Pure samples of UO//2(OH)//2 multiplied by (times) H//2O, beta -UO//2(OH)//2, and ' alpha -UO//3 multiplied by (times) 0. 85H//2O' have been synthesized. Pulsed NMR data from a wide temperature range have been interpreted in terms of structural features and proton motions for all three materials. Two types of water molecule reorientation have been observed in UO//2(OH)//2 multiplied by (times) H//2O and characterized in terms of activation energies and correlation times for the motions (Motion A: T//c equals 2. 2 plus or minus 0. 5 multiplied by 10** minus **1**5 sec, E//A equals 29. 0 plus or minus 4 kJ mole** minus **1; Motion B: T//c equals 4 plus or minus 0. 5 multiplied by 10** minus **1**3 sec, E//A equals 31. 2 plus or minus 4 kJ mole** minus **1).