We analyse the effect of Au impurities, diffused onto GaSb substrates, on the formation of nanodot hexagonal arrays created by low energy argon ion sputtering. It is concluded that oblique incidence in rotating configuration most probably delays the formation of the nanodots compared to previously reported normal incidence experiments. The presence of cracks induced by the sputtering process has been observed only in the Audiffused sample. For the same sputtering conditions, the dimensions of the dots in the Au-diffused sample are larger than in the case of the pure sample. However, they keep the same shape in both cases. Energy dispersive X-ray analysis revealed that the sputtering induces a more pronounced Ga enrichment in the case of Au-diffused sample. (c) 2007 Elsevier B.V. All rights reserved.