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Small angle X-ray scattering (SAXS) measurements of nanomaterials

Background

Rigaku's patented Cross Beam Optics (CBO) SAXS design allows SAXS measurements to 0.1 in q (65 nm) to be performed routinely and in direct complement to other wide angle scattering and diffraction methods. Both solid and liquid samples can be measured in a wide range of SAXS geometries, including glancing incidence (GISAXS).

SAXS applications include:

  • Macromolecular structure and orientation in polymeric materials
  • Particle size distributions of nanoparticles suspended in solution
  • Particle/pore size distributions in deposited or bulk solid nanomaterials
  • Molecular morphology and orientation in nanocomposites

Investigation

Transmission SAXS from nano-particles suspended in solution is a powerful method for the determination of particle sizes and shapes. The requirement for accurate size and shape information is important in many of the emerging areas of nanomaterials research currently taking place throughout the world. The Ultima IV with CBO offers one touch switching from conventional wide angle scattering and diffraction geometries to the ultra-low angle performance needed for SAXS measurements.

(SAXS) measurements of nanomaterials1

In this example the experimental SAXS curve (above ) has been overlaid with the calculated SAXS curves from a bimodal distribution of particle sizes (below) modeled in NanoSolver, Rigaku's powerful software solution for SAXS data processing. The agreement between the experimental and calculated curves shows that the proposed distribution model is in good agreement with what is actually contained in the sample, as observed by TEM.

(SAXS) measurements of nanomaterials2

In addition to transmission measurements the CBO SAXS geometry with automatically aligned sample stage is capable of performing reflection SAXS. The figure below is a reflection SAXS measurement recorded from a 100 nm thin layer of Ni embedded C on Si. The figure shows output from NanoSolver displaying the overlaid experimental and calculated reflection SAXS curves. The agreement of the calculated and experimental curves suggest a broad distribution of Ni particle sizes ranging from 2 to 10 nm.

(SAXS) measurements of nanomaterials3