Stacking of hexagonal nanocrystal layers during Langmuir-Blodgett deposition

J Phys Chem B. 2012 May 24;116(20):6017-26. doi: 10.1021/jp3015436. Epub 2012 May 10.

Abstract

Hexagonally ordered close-packed monolayers of sterically stabilized FePt nanocrystals were deposited on substrates using the Langmuir-Blodgett technique. Monolayers of nanocrystals were also stacked by sequential Langmuir-Blodgett transfer. The structures of the nanocrystal monolayers and multilayer stacks were examined with scanning electron microscopy (SEM) and grazing-incidence small-angle scattering (GISAXS). An analytical model derived from the quasikinematic approximation provides a convenient description of the GISAXS data of the stacked layers. The transferred monolayers showed good in-plane hexagonal order, even for trilayers. Bilayers exhibited spatial registry with the top layer positioned above the 3-fold coordinated sites of the bottom layer. Trilayers, on the other hand, exhibited significant disorder.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Microscopy, Electron, Scanning
  • Nanoparticles / chemistry*
  • Scattering, Small Angle
  • X-Ray Diffraction