In situ structural kinetics of picosecond laser-induced heating and fragmentation of colloidal gold spheres. Issue 9 (25th February 2020)

• Record Type: Journal Article
• Authors: Ziefuss, Anna Rosa; Reich, Stefan; Reichenberger, Sven; Levantino, Matteo; Plech, Anton
• Is Part Of: Physical chemistry chemical physics. Volume 22:Issue 9(2020)
• Page Start: 4993
• Page End: 5001
• Publication Date: 2020-02-25
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c9cp05202j
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : The structural and energetic pathway of picosecond laser fragmentation of gold colloids has been clarified by time-resolved X-ray scattering. Abstract : Fragmentation of colloidal 54 nm gold nanoparticles by picosecond laser pulses is recorded by time-resolved X-ray scattering, giving access to structural dynamics down to a 80 ps resolution. Lattice temperature and energy dissipation have been quantified to verify that the maximum applied fluence of 1800 J m −2 heats up the particles close to boiling. Already within 30 ns, particles with significantly lower particle sizes of 2 to 3 nm are detected, which hints towards an ultrafast process either by a thermal phase explosion or Coulomb instability. An arrested growth is observed on a microsecond time scale resulting in a final particle size of 3–4 nm with high yield. In this context, the fragmentation in a NaCl/NaOH solution seems to limit growth by electrostatic stabilization of fragments, whereas it does not modify the initial product sizes. The laser-induced fragmentation process is identified as a single-step, instantaneous reaction.