Nanometer-scale patterning of alkali halide surfaces by ion bombardment

• Published in: Applied surface science Vol. 255; no. 5; pp. 1766 - 1775
• Main Authors: Saeed, S.R., Sinha, O.P., Krok, F., Szymonski, M.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 30-12-2008
• Subjects: Alkali halides; Atomic-force microscopy; Electronic desorption; Ion irradiation; Ripples; Surface modification; Surface morphology; Surface patterning; 64.60.Ht; Surface modification; 68.35.Bs; Ion irradiation; Atomic-force microscopy; Surface morphology; 61.80.Az; Electronic desorption; Alkali halides; Ripples; Surface patterning
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2008.06.043

Structural properties of alkali halide surfaces (KBr, KI, and RbI) have been modified by low energy Ar
+ ion beam bombardment. The morphology developed on the irradiated surfaces was investigated by the atomic-force microscopy (contact mode) under UHV conditions. The results indicate that for the incidence angles between 30° and 40° a periodic ripple morphology is developed with the ripple vector parallel to the beam direction, whereas for the angles larger than 60° the vector is perpendicular to the beam. The average surface roughness and the wavelength of the ion-induced periodic structures were measured as a function of the ion fluence (10
13–10
18
ions/cm
2), the beam energy (1–5
keV), and the sample temperature (from 300
K to 600
K). The results are explained in terms of a new atomic-scale model taking into account the fact that ion sputtering of alkali halides in the investigated energy range is dominated by electronic processes rather than ballistic collisions.