Formation of aggregated nanoparticle spheres through femtosecond laser surface processing

Alfred T. Tsubaki, Mark A. Koten, Michael J. Lucis, Craig Zuhlke, Natale Ianno, Jeffrey E. Shield, Dennis R. Alexander

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


A detailed structural and chemical analysis of a class of self-organized surface structures, termed aggregated nanoparticle spheres (AN-spheres), created using femtosecond laser surface processing (FLSP) on silicon, silicon carbide, and aluminum is reported in this paper. AN-spheres are spherical microstructures that are 20–100 μm in diameter and are composed entirely of nanoparticles produced during femtosecond laser ablation of material. AN-spheres have an onion-like layered morphology resulting from the build-up of nanoparticle layers over multiple passes of the laser beam. The material properties and chemical composition of the AN-spheres are presented in this paper based on scanning electron microscopy (SEM), focused ion beam (FIB) milling, transmission electron microscopy (TEM), and energy dispersive x-ray spectroscopy (EDX) analysis. There is a distinct difference in the density of nanoparticles between concentric rings of the onion-like morphology of the AN-sphere. Layers of high-density form when the laser sinters nanoparticles together and low-density layers form when nanoparticles redeposit while the laser ablates areas surrounding the AN-sphere. The dynamic nature of femtosecond laser ablation creates a variety of nanoparticles that make-up the AN-spheres including Si/C core-shell, nanoparticles that directly fragmented from the base material, nanoparticles with carbon shells that retarded oxidation, and amorphous, fully oxidized nanoparticles.

Original languageEnglish (US)
Pages (from-to)778-787
Number of pages10
JournalApplied Surface Science
StatePublished - Oct 15 2017


  • Core-shell
  • Femtosecond laser
  • Laser processing
  • Nanoparticle aggregates
  • Onion-like

ASJC Scopus subject areas

  • Chemistry(all)
  • Condensed Matter Physics
  • Physics and Astronomy(all)
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films


Dive into the research topics of 'Formation of aggregated nanoparticle spheres through femtosecond laser surface processing'. Together they form a unique fingerprint.

Cite this