Mechanisms of surface nanostructuring of Al2O3 and MgO by grazing incidence irradiation with swift heavy ions

• DOI: 10.1016/j.surfin.2021.101508
• Publication Date: 2021-10-08T08:04:52Z
• Authors: M. Karlušić; R.A. Rymzhanov; J.H. O'Connell; L. Bröckers; K. Tomić Luketić; Z. Siketić; S. Fazinić; P. Dubček; M. Jakšić; G. Provatas; N. Medvedev; A.E. Volkov; M. Schleberger
• Keywords: Condensed Matter - Materials Science; atomic force microscopy; Physics; ion irradiation; irradiation effects; Materials Science (cond-mat.mtrl-sci); FOS: Physical sciences; MD simulation; 02 engineering and technology; Physik (inkl. Astronomie); 01 natural sciences; 0103 physical sciences; swift heavy ion; 0210 nano-technology; ion irradiation ; irradiation effects ; swift heavy ion ; atomic force microscopy ; MD simulation

We experimentally discovered that Al2O3 and MgO exhibit well-pronounced nanometric modifications on the surfaces when irradiated under grazing incidence with 23 MeV I beam, in contrast to normal incidence irradiation with the same ion beam when no damage was found. Moreover, ions in these two materials produce notably different structures: grooves surrounded with nanohillocks on MgO surfaces vs. smoother, roll-like discontinuous structures on the surfaces of Al2O3. To explain these results, detailed numerical simulations were performed. We identified that a presence of the surface inhibits recrystallization process, thereby preventing transient tracks from recovery, and thus forming observable nanopatterns. Furthermore, a difference in the viscosities in molten states in Al2O3 vs. MgO explains the differences in the created nanostructures. Our results thus provide a deeper understanding of the fundamental processes of surface nanostructuring, potentially allowing for controlled production of periodic surface nanopatterns.