The ion beam milling method uses high-energy argon ion bombardment to remove material or
modify the surface of a sample. An ion gun directs energetic argon ions toward the sample, which is placed so that the surface is bombarded at a controlled angle. A low angle of ion incidence with respect to the sample surface gradually removes surface layers of material at the atomic level - cleaning and polishing the sample. Surface modification to produce contrast or microstructure can be realized with higher milling angles up to 90°. Thus, ion beam milling effectively removes contamination and mechanically deformed material to produce nearly artifact-free surfaces for SEM and light microscopy inspection.