Simple dynamical model that leads to sputter cone formation.

Area of Science:

• Surface physics
• Materials science
• Computational modeling

Background:

• Sputter cone formation is a common phenomenon in materials processing.
• Existing models often lack simplicity or fail to capture key dynamics.

Purpose of the Study:

• To develop a simplified yet comprehensive model for sputter cone formation.
• To investigate the influence of sputter yield angular dependence and surface diffusion on cone morphology.

Main Methods:

• Introduction of a novel computational model incorporating angular sputter yield and fourth-order smoothing (surface diffusion).
• 1D and 2D simulations to observe sputter cone evolution under various initial conditions.

Main Results:

• The model successfully predicts sputter cone formation across diverse initial conditions.
• Cone opening angle is shown to be independent of the specific initial condition.
• In 2D, sputter cones are analogs of undercompressive shocks, forming pyramids from orthogonal shock superpositions.

Conclusions:

• The proposed model provides a fundamental understanding of sputter cone formation dynamics.
• Surface diffusion and angular sputter yield are critical factors governing cone geometry.
• The connection to undercompressive shocks offers new theoretical insights into pattern formation.