Development of Knife-Edge Ridges on Ion-Bombarded Surfaces

TL;DR

This paper demonstrates that ion bombardment can create high-slope knife-edge ridges on surfaces, with potential applications in surface patterning and fabrication, supported by laboratory and numerical experiments.

Contribution

It introduces a novel method for fabricating knife-edge ridges through ion bombardment, showing universality and independence from initial conditions.

Findings

Ridges form from pre-fabricated pits expanding under ion bombardment.

Collision of pits creates stable knife-edge ridges.

Ridge shape and propagation speed are universal and predictable.

Abstract

We demonstrate in both laboratory and numerical experiments that ion bombardment of a modestly sloped surface can create knife-edge like ridges with extremely high slopes. Small pre-fabricated pits expand under ion bombardment, and the collision of two such pits creates knife-edge ridges. Both laboratory and numerical experiments show that the pit propagation speed and the precise shape of the knife edge ridges are universal, independent of initial conditions, as has been predicted theoretically. These observations suggest a novel method of fabrication in which a surface is pre-patterned so that it dynamically evolves to a desired target pattern made of knife-edge ridges.