MAGNETIC STUDIES ON SCYU1-YO2+X SOLID-SOLUTIONS

Magnetic susceptibilities of Sc//yU//1// minus //yO//2// plus //x solid solutions have been measured from 2. 7 K to room temperature. The magnetic moment and Weiss constant have been determined in the temperature range in which the Curie-Weiss law holds. For the solid solutions showing antiferromagnetic transition, the Neel temperature has also been determined. The substitution of Sc**3** plus for U**4** plus was found to effect not only magnetic dilution of UO//2, but also oxidation of U**4** plus to U**5** plus . Excess oxygen ions which entered the interstitial sites, weakened the antiferromagnetic interaction between uranium ions and oxidized U**4** plus to U**5** plus . The effect of oxygen vacancies on the antiferromagnetic interaction was small in the concentration range of this experiment (0. 8 a/o).