Effect of deformation nanostructuring on ion-beam erosion of copper

Abstract

The effect of deformation nanostructuring on ion-beam erosion of copper at high fluences of irradiation with 30 keV argon ions was experimentally studied. Deformation nanostructuring by high-pressure torsion was used to form an ultrafine grained structure with a grain size of ~0.4 µm in copper samples with an initial grain size about 2 µm. It was found that when a layer of thickness comparable to the grain size was sputtered, a steady-state cone-shaped relief was formed on the copper surface, the appearance of which did not change with increasing irradiation fluence. It has been shown that the smaller the grain size in copper, the greater the concentration and the smaller the cone height on the surface. The cone inclination angles, close to 82°, as well as the sputtering yield of 9.6 at./ion, practically does not depend on the copper grain size, the thickness of the sputtered layer, and the irradiation fluence. Calculations using the SRIM code showed that when taking into account the sputtering of atoms from the walls of the cones, the sputtering yield of a cone-shaped copper relief Үc, was 3.5 times less than the yield of a single cone, 1.2 times greater than the sputtering yield of a smooth surface, and the value of 9.25 at./ion was close to the experimentally measured one.