Femtosecond Laser-Induced Periodic Surface Structures in Titanium-Doped Diamond-like Nanocomposite Films: Effects of...

Area of Science:

• Materials Science
• Nanotechnology
• Laser Physics

Background:

• Laser-induced periodic surface structures (LIPSS) are crucial for modifying material surfaces.
• Titanium-doped diamond-like nanocomposite (DLN) films offer unique properties for advanced applications.
• Understanding LIPSS formation mechanisms is key to controlling surface morphology.

Purpose of the Study:

• Investigate LIPSS formation on Ti-DLN films using femtosecond laser ablation.
• Analyze the influence of laser polarization and scanning parameters on LIPSS characteristics.
• Evaluate the nanofriction properties of the generated LIPSS.

Main Methods:

• Femtosecond laser ablation of Ti-DLN a-C:H:Si:O films with linearly polarized beams (515 nm, 320 fs).
• Systematic variation of pulse repetition rates (100 kHz-2 MHz) and scanning velocities (0.05-1 m/s).
• Atomic force microscopy (AFM) in lateral force mode to assess nanofriction.

Main Results:

• LSFL orientation is consistently perpendicular to the laser polarization direction.
• LSFL periods range from 360 ± 5 nm (parallel to scanning) to 420 ± 10 nm (perpendicular to scanning).
• Nanofriction behavior is dependent on LIPSS orientation relative to the AFM tip scanning direction.

Conclusions:

• LIPSS formation on Ti-DLN films is governed by laser polarization and scanning dynamics.
• The surface plasmon polaritons model explains the observed LIPSS formation.
• Controlled surface structuring of Ti-DLN films can tune their tribological properties.