Strong vortex pinning in the low-temperature superconducting phase of (U_1-xTh_x)Be_13

Ana Celia Mota, Elisabeth Dumont, James L. Smith

We have found a sharp transition at T_c2=350 mK in the vortex creep rate of a single crystal of (U_1-xTh_x)Be_13 with T_c=523 mK (x=0.0275). For T<<T_c2, no creep of vortices is ob…