The wetting of UC by copper and gold

Abstract

Single crystals of α-Al2O3 were irradiated with 238U ions using two different energies: 3.4 MeV/u and 1.7 MeV/u. The irradiations were performed at a temperature of ≈ 80 K, with fluences ranging from 1.2 × 1012 to 2.5 × 1012 ions cm−2. After irradiation, thin gold films were deposited on the sapphire surfaces by using a sputtering method. Subsequent annealing in air at a temperature of 723 and 923 K were applied to investigate the influence of the pre-damage on the adhesion of the gold layer on the sapphire surface. Rutherford backscattering analysis and scanning electron microscopy performed in both virgin and irradiated areas, show that the pre-irradiation damage inhibits the gold film of breaking up into islands after annealing. A wetting effect, which could depend on the damage morphology, is clearly observed.