Effect of viscous flow on ion damage near solid surfaces

Mechanism of surface modification in the plasma-surface interaction in electrical arcs

“…These energies are typical for ion irradiation of materials, and are well known to form heat spikes that can cause massive atom redistribution and relocation, sometimes resulting in cratering. 15,36 The other important result obtained from the PIC simulations is that the ion flux is very high, the total flux ⌫ of both ions and neutrals over all energies being almost ϳ10 25 ions/ cm 2 / s. This flux obtained from PIC may seem very high compared to typical ion irradiation fluxes which are 5-15 orders of magnitude lower 42,43 but a simple estimate from experimental values of the typical currents in arcs on the order of I = 10 A and final crater areas on the order of A = ͑10 m͒ 2 ͑Ref. 3͒ gives a comparable flux of I / e / A =6 ϫ 10 25 ions/ cm 2 / s ͑e is the electron charge͒.…”

“…[17][18][19][20] The single-atom cratering, by contrast, is now well established to be caused by liquid flow, associated with the formation of a "heat spike," i.e., hot pressurized matter formed after high-energy incoming ions are thermalized in a sequence of ballistic collisions. 15,16,21,22 Although both the macroscopic and atom-induced craters bear a clear visual resemblance to the craters produced by arcing, the possible relation between arc and impact cratering mechanisms has not been established.…”

“…Formation of craters is, on the other hand, also observed on planets and moons due to asteroids, 12 on materials hit by high-velocity projectiles, 13 and surprisingly also on the atomic scale due to single accelerated ions and atom clusters hitting surfaces. 14,15 Quite recently all these ranges of cratering were linked together, when it was shown that the craters produced by atom clusters of sizes of roughly 10 000 or more atoms produce cratering due to the same pressurerelated mechanism as the macroscopic impactors. 16 When this size has been reached, the crater formation in the atomistic simulations follows the same scaling law as the macroscopic impacts over about 35 orders of magnitude in size scale 16 and exhibits all the central features of experimental cratering, such as splashing, crown, and corona formation.…”

Influence of ion energy and substrate temperature on the optical and electronic properties of tetrahedral amorphous carbon (ta-C) films

“…[44][45][46] In context of the thermal spike, the pronounced effect of deposition temperature is rather surprising as it is difficult, at first sight, to understand how the substrate temperature of this order is significant when energies well in excess of 10 4 K occur in the thermal spike. Below, we offer a preliminary description which shows that the effect of deposition temperature may be significant in the later stages of the thermal spike.…”

Comparison of molecular dynamics and binary collision approximation simulations for atom displacement analysis

“…[12,13,14,15] Previous studies have shown that small changes in the shape of craters can lead to significant changes in macroscopic pattern-forming behavior. [16] Hence well-converged, accurate simulations are an essential input to crater function theory for drawing conclusions about surface stability or large-scale pattern formation.…”