Further theoretical refinements of BH’s model have been proposed to underline the secondary effect of local curvature-dependent sputtering, ion beam-induced smoothing, and hydro-dynamical contribution [7, 8]. BH’s linear and its extended models explain many experimental observations but suffered many limitations also [9–11]. Investigations this website by Madi et al. [11] and Norris et al. [12] showed that the ion impact-induced mass redistribution is the prominent cause of surface patterning and smoothening for high and low angles, respectively. Castro et al. [13, 14] proposed the generalized framework of hydrodynamic approach, which considers ion impact-induced

stress causing a solid flow inside the amorphous layer. They pointed out that the surface evolution with ion beam is an intrinsic property of the dynamics of the amorphous surface layer [15]. All above experimental findings and their theoretical justification raise questions on lack of a single physical mechanism

ABT-263 on the origin and evolution of ripples on solid surface. In this work, we propose a new approach for explaining all ambiguity related to the origin of ripple formation. We argue that amorphous-crystalline interface (a/c) plays a crucial role in the evolution of ripples. We have shown that the ion beam-induced incompressible solid flow in amorphous layer starts the mass rearrangement at a/c interface which is responsible for ripple formation on the free surface rather than earlier mentioned models of curvature-dependent erosion and mass redistribution

at free surface. Presentation of the hypothesis In order to study the role of a/c interface in surface patterning of Si (100) surface during irradiation, we performed a series of experiments by preparing two Quisqualic acid sets of samples with different depth locations of a/c interface. The variation in depth location of a/c interface is achieved by irradiating the Si surface using 50 keV Ar+ ion at a fluence of 5 × 1016 ions per square centimeter (for full amorphization) at different angles of incidence, viz, 60° (sample set A) and 0° (sample set B) with respect to surface normal. The depth location of a/c interface would be higher in set B samples as compared to set A samples due to higher projected ion range for 0° as compared to 60° ion beam irradiation. Figure 1a,b shows the schematic view for ion beam-stimulated damage range for off-normal incidence of ion beam at 60° (named as set A) and normal incidence (named as set B), respectively. Subsequently, to grow ripples in the www.selleckchem.com/products/defactinib.html second stage of irradiation, both sets of samples were irradiated at an angle of 60° wrt surface normal using 50 keV Ar+ ion beam, as shown in Figure 1c,d. For the set A samples, ion beam-stimulated damage effect will reach at a/c interface in the second stage irradiation while it remains inside the amorphous layer for set B samples due to deeper depth location of a/c interface.