Journal of Nanoparticle Research

, Volume 4, Issue 5, pp 423–432 | Cite as

Bimodal Nanoparticle Size Distributions Produced by Laser Ablation of Microparticles in Aerosols

  • William T. Nichols
  • Gokul Malyavanatham
  • Dale E. Henneke
  • Daniel T. O'Brien
  • Michael F. Becker
  • John W. Keto


Silver nanoparticles were produced by laser ablation of a continuously flowing aerosol of microparticles in nitrogen at varying laser fluences. Transmission electron micrographs were analyzed to determine the effect of laser fluence on the nanoparticle size distribution. These distributions exhibited bimodality with a large number of particles in a mode at small sizes (3–6-nm) and a second, less populated mode at larger sizes (11–16-nm). Both modes shifted to larger sizes with increasing laser fluence, with the small size mode shifting by 35% and the larger size mode by 25% over a fluence range of 0.3–4.2-J/cm2. Size histograms for each mode were found to be well represented by log-normal distributions. The distribution of mass displayed a striking shift from the large to the small size mode with increasing laser fluence. These results are discussed in terms of a model of nanoparticle formation from two distinct laser–solid interactions. Initially, laser vaporization of material from the surface leads to condensation of nanoparticles in the ambient gas. Material evaporation occurs until the plasma breakdown threshold of the microparticles is reached, generating a shock wave that propagates through the remaining material. Rapid condensation of the vapor in the low-pressure region occurs behind the traveling shock wave. Measurement of particle size distributions versus gas pressure in the ablation region, as well as, versus microparticle feedstock size confirmed the assignment of the larger size mode to surface-vaporization and the smaller size mode to shock-formed nanoparticles.

bimodal size distribution nanoparticle synthesis laser ablation aerosol processing 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Andres R.P., J.D. Bielfeld, J.I. Henderson, D.B. Janes, V.R. Kolagunta, C.P. Kubiak, W.J. Mahoney & R.G. Osifchin, 1996. Self-assembly of a two-dimensional superlattice of molecularly linked metal clusters. Science 273, 1690-1693.Google Scholar
  2. Becker M.F., J.R. Brock, H. Cai, D.E. Henneke, J.W. Keto, J. Lee, W.T. Nichols & H.D. Glicksman, 1998. Metal nanoparticles generated by laser ablation. Nanostruc. Mat. 10, 853-863.Google Scholar
  3. Camata R.P., M. Hirasawa, K. Okuyama & K. Takeuchi, 2000. Observation of aerosol formation during laser ablation using a low-pressure differential mobility analyzer. J. Aerosol Sci. 31, 391-401.Google Scholar
  4. Cai H., N. Chaudhary, J. Lee, M.F. Becker, J.R. Brock & J.W. Keto, 1998. Generation of metal nanoparticles by laser ablation of microspheres. J. Aerosol. Sci. 29, 627-636.Google Scholar
  5. Ehrman S.H. & S.K. Friedlander, 1999. Bimodal distributions of two component metal oxide aerosols. Aerosol Sci. Technol. 30, 259-272.Google Scholar
  6. Feldheim D.L. & C.D. Keating, 1998. Self-assembly of single electron transistors and related devices. Chem. Soc. Rev. 27, 1-12.Google Scholar
  7. Gagliano F.P. & U.C. Paek, 1974. Observation of laser-induced explosion of solid materials and correlation with theory. Appl. Opt. 13, 274-279.Google Scholar
  8. Geohegan D.B., A.A. Puretzky, G. Duscher & S.J. Pennycook, 1998. Time resolved imaging of gas phase nanoparticle synthesis by laser ablation. Appl. Phys. Lett. 72, 2987-2789.Google Scholar
  9. Granqvist C.G. & R.A. Buhrman, 1976. Ultrafine metal particles. J. Appl. Phys. 47, 2200-2219.Google Scholar
  10. Haglund R.F., 1998. In: Hummel R.E. and Wilsmann P. eds. Handbook of Optical Properties, Vol. II Optics of Small Particles, Interfaces and Surfaces, CRC Press, New York, pp. 191-231.Google Scholar
  11. Henneke D.E., 2002. Ph.D. Dissertation, The University of Texas at Austin.Google Scholar
  12. Jung Th., H. Burtscher & A. Schmidt-Ott, 1988. Multiple charging of ultrafine aerosol particles by aerosol photoemission. J. Aerosol Sci. 19, 485-490.Google Scholar
  13. Kiely C.J., J. Fink, M. Brust, D. Bethell & D.J. Schiffrin, 1998. Spontaneous ordering of bimodal ensembles of nanoscopic gold clusters. Nature 396, 444-446.Google Scholar
  14. Kreibig U. & M. Vollmer, 1995. Optical Properties of Metal Clusters. Berlin Springer-Verlag.Google Scholar
  15. Lee J., M.F. Becker & J.W. Keto, 2001. Dynamics of laser ablation of microparticles prior to nanoparticle generation. J. Appl. Phys. 89, 8146-8152.Google Scholar
  16. Miller J.C. & D.B. Geohegan, 1994. Laser Ablation: Mechanisms and Applications II. American Institute of Physics, New York.Google Scholar
  17. Miller J.C. & R.F. Haglund, 1998. Laser Ablation and Desorption. Academic Press, San Diego.Google Scholar
  18. Murray C.B., D.J. Norris & M.G. Bawendi, 1993. Synthesis and characterization of nearly monodisperse CdE (E = S, Se, Te) semiconductor nanocrystallites. J. Am. Chem. Soc. 115, 8706-8715.Google Scholar
  19. Nichols W.T., G. Malyavanatham, D.E. Henneke, J.R. Brock, M.F. Becker, J.W. Keto & H.D. Glicksman, 2000. Gas and pressure dependence for the mean size of nanoparticles produced by laser ablation of flowing aerosols. J. Nanoparticle Res. 2, 141-145.Google Scholar
  20. Nichols W.T., J.W. Keto, D.E. Henneke, J.R. Brock, G. Malyavanatham, M.F. Becker & H.D. Glicksman, 2001. Large-scale production of nanocrystals by laser ablation of microparticles in a flowing aerosol. Appl. Phys. Lett. 78, 1128-1130.Google Scholar
  21. Ohara P.C., D.V. Leff, J.R. Heath & W.M. Gelbart, 1995. Crystallization of opals from polydisperse nanoparticles. Phys. Rev. Lett. 75, 3466-3469.Google Scholar
  22. Söderlund J., L.B. Kiss, G.A. Niklasson & C.G. Granqvist, 1998. Lognormal size distributions in particle growth processes without coagulation. Phys. Rev. Lett. 80, 2386-2389.Google Scholar
  23. Taruta S., T. Takano, N. Takusagawa, K. Okada & N. Otsuka, 1996. Liquid phase sintering of bimodal size distributed alumina powder mixtures. J. Mat. Sci. 31, 573-579.Google Scholar

Copyright information

© Kluwer Academic Publishers 2002

Authors and Affiliations

  • William T. Nichols
    • 1
  • Gokul Malyavanatham
    • 2
  • Dale E. Henneke
    • 3
  • Daniel T. O'Brien
    • 4
  • Michael F. Becker
    • 4
  • John W. Keto
    • 1
  1. 1.Department of PhysicsThe University of Texas at AustinAustinUSA
  2. 2.Department of Materials Scienceand EngineeringThe University of Texas at AustinAustinUSA
  3. 3.Department of Chemical EngineeringThe University of Texas at AustinAustinUSA
  4. 4.Department of Electrical and Computer EngineeringThe University of Texas at AustinAustinUSA

Personalised recommendations