Electronic properties of γ-U and superconductivity of U-Mo alloys

Fundamental electronic properties of gamma-Uranium were determined using Mo doping combined with ultrafast (splat) cooling, which allowed stabilization of the bcc structure to low temperatures. The Sommerfeld coefficient gamma e is enhanced to 16 mJ/mol K-2 from 11 mJ/mol K-2 for alpha-U. Magnetic susceptibility remains weak and T-independent, approximate to 5 x 10 (8) m(3)/mol. The Mo-doped gamma-U exhibits a conventional BCS superconductivity with T-c approximate to 2.1 K and critical field exceeding 5 T for 15 at.% Mo. This type of superconductivity is qualitatively different from the one found for pure U splat, which has T-c higher than 1 K but the weak specific heat anomaly proves that it is not real bulk effect. (C) 2013 Elsevier B.V. All rights reserved.