Surface patterning in thin ternary composites based on Zr, In and C irradiated with 2 MeV W+ ions

A number of sophisticated methods are related to the technology of thin-film complex materials. One of them, although less used, is the sputtering of targets with low-energy ions. Using this method, various thin multi-element composites can be formed either as amorphous mixtures or crystalline structures (e.g. MAX phases), or something in between. In this work, 25 keV Ar+ ion sputtering was used to synthesize thin ternary systems based on Zr, In, and C with a stoichiometric ratio of ∼2:1:1. The prepared samples were exposed to 2 MeV W+ ion irradiation (for comparison, 1/3 of each sample remained pristine) to determine their response to heavy ion bombardment. The analysis was focused mainly on the surface morphology. It has been shown that using ion sputtering, thin ternary composites with a very smooth surface and homogeneously distributed phases can be prepared. After ion bombardment, well distinct self-organized structures appeared – parallel nanostripes growing in several directions on both irradiated and unirradiated regions of the composites. As a driving force of the patterns, an immiscibility of the building elements In and C was proposed. The process of the self-assembly consists in the coordinated expansion of the phase separation that occurs at elevated temperatures induced by ion irradiation. The results indicate that using ion beam sputtering with subsequent MeV ion bombardment, multi-element thin-film composites exhibiting self-organized morphology can be synthesized.