title: X-ray mapping of nanoparticle superlattice thin films.
abstract: We combine grazing-incidence and transmission small-angle X-ray diffraction with electron microscopy studies to characterize the structure of nanoparticle films with long-range order. Transmission diffraction is used to collect in-plane diffraction data from single grains and locally aligned nanoparticle superlattice films. Systematic mapping of samples can be achieved by translating the sample in front of the X-ray beam with a spot size selected to be on the order of superlattice grain features. This allows a statistical determination of superlattice grain size and size distribution over much larger areas than typically accessible with electron microscopy. Transmission X-ray measurements enables spatial mapping of the grain size, orientation, uniformity, strain, or crystal projections and polymorphs. We expand this methodology to binary nanoparticle superlattice and nanorod superlattice films. This study provides a framework for characterization of nanoparticle superlattices over large areas which complements or expands microstructure information from real-space imaging.
authors.affiliation: Department of Chemistry, ‡Department of Materials Science and Engineering, and §Department of Electrical and Systems Engineering, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Benjamin T
authors.initials: BT
authors.lastname: Diroll
authors.forename: Vicky V T
authors.initials: VV
authors.lastname: Doan-Nguyen
authors.forename: Matteo
authors.initials: M
authors.lastname: Cargnello
authors.forename: E Ashley
authors.initials: EA
authors.lastname: Gaulding
authors.forename: Cherie R
authors.initials: CR
authors.lastname: Kagan
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Murray
keywords: GISAXS; SAXS; grain size; mapping; nanoparticle superlattice