Field ion microscopy of nanoblocks on the surface of metals after irradiation argon ion beams

The interaction of metal (Pt) with beams accelerated to energy E=30 keV positive ions of argon, and a fluence of F = 1016, and 1017 ion/cm2 at ion current densities of 150 A/cm2 (T=70°C) and 200 A/cm2 (T=200°C), respectively, were detected education effect of nano blocks. The analysis of the surface modification, the subsurface volume and boundary area of nano blocks on the basis of the results obtained by the method of field ion microscopy. It is assumed that the contrast boundary areas nano blocks correspond to the atomic structure of depleted zones. For a fluence of F = 1016 ion/cm2 nano blocks was observed in the layer with thickness ~ 1.5 nm from the irradiated surface. With increasing fluence up to F=1017 ion/cm2 the effect of the formation of nano crystalline block structure (with blocks of size 1-5 nm) is observed in the near-surface volume thickness of not less than 20 nm from the irradiated surface. From the analysis of experimental data, the mechanism of formation of such zones is more likely associated with the effect of channeling. The dimensions of the nano blocks had defined on the irradiated surface Pt and subsurface volume of material. On the surface after irradiation with a fluence of 1016 ion/cm2, the proportion of units with an average size of 1 nm was 60%. The average size of the blocks ranged from 1-5 nanometers with increase in distance up to 20 nm in depth.