Isotope Effect in Superconductingγ-Uranium Alloys

Abstract

We have measured the isotope effect in stablized 7-uranium alloys and found T c ozM a , a= -0.53±0.02. We find r c »2.1°K to be a more representative value for the extrapolated superconducting transition temperature of a hypothetical pure 7-uranium than the previously reported estimate of 1.8°K.

Characterization of cubic γ-phase uranium molybdenum alloys synthesized by ultrafast cooling

“…The T c value for the U-15 at.% Mo alloy actually agrees well with that (2.11 K) reported in [30]. However, under normal furnace cooling conditions this alloy displayed the c°-structure [30], while our splat-cooled sample consists of a pure c phase. A broader transition (in comparison with the pure U-splat) was observed for the two c°-phase alloys with 11 at.% Mo (DT c = 0.5 K) and 12 at.% Mo (DT c = 0.3 K).…”

“…The T c value for all three c-phase samples is somewhat lower than the values reported for the water-quenched alloys with similar Mo contents [19]. The T c value for the U-15 at.% Mo alloy actually agrees well with that (2.11 K) reported in [30]. However, under normal furnace cooling conditions this alloy displayed the c°-structure [30], while our splat-cooled sample consists of a pure c phase.…”

Electronic Energy Band Structure of the Actinide Metals

“…As mentioned earlier, there is considerable speculation as to the nature of the 5f electrons in both a-and y-uranium (Hill et al, 1967). From the charge densities shown in Fig.…”