Structural analysis of simulated fission-produced noble metal alloys and their superconductivities

Ternary (Mo-Ru-Pd) and binary (Mo-Ru, Mo-Pd) alloys have been prepared usin g an Ar are melting furnace. Mo and the noble metals, Ru and Pd, are the co nstituents of metallic insoluble residues, which were found in the early da ys of post-irradiation studies on uranium oxide fuels. In the present study , the structure of the alloys was evaluated using a powder X-ray diffractom eter. Unit cell parameters were determined by least squares refinements of powder X-ray diffraction data. Scanning electron microscopic analyses of th e surface of the alloys indicated that surface morphology was dependent on the crystallographic structure as well as its composition. Measurements of the magnetic susceptibility of the alloys showed evidence of superconductin g transition from 3 to 9.2 K. Among the ternary and binary alloys, the sigm a -phase showed the highest superconducting transition temperature, similar to9.2 K.