Rietveld analysis and maximum entropy method of powder diffraction for bundles of single-walled carbon nanotubes

TL;DR

This paper presents a refined analysis method combining Rietveld analysis and maximum entropy method to accurately determine the structure of single-walled carbon nanotube bundles from powder diffraction data.

Contribution

It introduces a novel pattern fit technique for SWNT diffraction data and demonstrates the combined use of Rietveld analysis with MEM for detailed structural reconstruction.

Findings

Precise structure parameters for SWNT bundles obtained.

Successful reconstruction of carbon density and cavity emptiness in SWNT.

Method enhances structural analysis accuracy for nanotube materials.

Abstract

The structure of bundles of single-walled carbon nanotubes (SWNT) has been refined by Rietveld analysis using neutron and X-ray powder diffraction data. Based on previous simulation studies of powder diffraction data of SWNT and standard Rietveld analyses, we have developed a pattern fit technique for SWNT which provides precise structure parameters. We also show that the present technique can be used with the maximum entropy method (MEM), which is complementary to the Rietveld analysis. Using the neutron diffraction data of pristine SWNT, we have successfully reconstructed the density of carbon nuclei and zero density in the inner cavity of SWNT by MEM.