STRUCTURAL AND PHYSICAL-PROPERTIES OF ACTINIDE MATERIALS AT HIGH-PRESSURE

Selected results of in situ high pressure studies of actinide metals and compounds are described. A comparison is attempted between the pressure-induced structural phase transitions of UAs, UO2 and Th3P4 and the optical response of these compounds at high pressure. The structural properties of UTe, USe and PuSb at high pressure are compared with their electrical and magnetic properties. In certain cases a clear correlation could be established between a structural phase transition at room temperature and changes in reflectivity at the same temperature or in electrical resistance at temperatures between room temperature and 1.3 K. However, for some of the materials discussed the evolution of the physical properties is largely independent of the structural phase transitions.