Nanostructured surfaces

Ion nanostructuring of crystal surfaces and processes of self-organization
Zayachuk D.M.
Lviv Polytechnic National University, S. Bandera Str., 12, Lviv-79013, Ukraine 
E-mail: zayachuk@polynet.lviv.ua

Ion beam treatment is widely used for structuring the surface of solids, which is of great practical importance for various technical and technological applications. The main approach suggested to describe the process of individual surface structure formation under impact of ion beam bombardment is top-down, based on etching of solid surface by energetic ions, the sputter yield of which depends on the local surface curvature. In this report the issue of interaction of ion beams with a crystalline surface is considered from the point of view of impact on nanostructuring of the sputtering surfaces of the processes of self-organization of the planes of high reticular density and easy cleaving basing on the results of our recent studies of SnTe and PbTe crystals [1,2].
 SnTe and PbTe crystals are characterized by the same planes of high reticular density. SnTe crystals do not cleave, and for PbTe crystals the planes of high reticular density are also planes of easy cleavage. As a result the prolonged treatment of surfaces of these compounds with ion beams leads to the dominance of different ion-induced structures on their sputtering surfaces. In the case of SnTe, sharpened cones dominate on the structured surface. In the case of PbTe, sharpened conical structures are transformed into pyramidal structures. Their shape and lateral surface condition are determined by the crystallographic orientation of the sputtering surface and the self-organization of the planes of high reticular density in the process of formation of the pyramidal structure facets. The mechanisms of self-organization and the interplay between the reticular density of the sputtered surfaces and the surfaces of the lateral facets of ion-induced pyramidal nano- and microstructures are analyzed.

1.	D.M. Zayachuk, Y.D. Zayachuk, Cs. Buga, V.E. Slynko, and A. Csík, Near-non-preferential sputtering of multicomponent solids as an effective way for production of dense cone shape arrays on a sputtered surface, Vacuum 186 (2021) 110058, doi.org/10.1016/j.vacuum.2021.110058
2.	D.M. Zayachuk, Y.D. Zayachuk, M. Hunyadi, V.E. Slynko, and A. Csík, Transformations of micron-sized PbTe surface structures induced by low energy ions, J. All. Comp. 883 (2021) 160978, doi.org/10.1016/j.jallcom.2021.160978