Ion beam mixing and superconductivity in Cu-Bi

Ion beam mixing in Cu-Bi bilayered samples was studied using measurements of the superconducting transition temperature, T_c, backscattering analysis and electron microscopy. All measurements could be performed in situ, without warming above the irradiation temperature. Irradiation of the bilayered samples with energetic Kr⁺ at 10 K induces an amorphous phases which is also superconducting below ∼ 5.2. On annealing, complete recrystallization did not occur until room temperature. The backscattering results revealed that irradiation at 10 K causes significant interdiffusion of Cu and Bi but that at 295 K, there is essentially no mixing.