Neutron powder diffraction atomic pair distribution function analysis using the ARCS chopper spectrometer at the Spallation Neutron Source

TL;DR

This paper demonstrates the first neutron powder diffraction atomic pair distribution functions obtained from the ARCS spectrometer at the Spallation Neutron Source, showing high-quality data suitable for quantitative analysis.

Contribution

It introduces a method to acquire reliable neutron powder diffraction PDFs using the ARCS spectrometer in white-beam mode, expanding capabilities for structural analysis.

Findings

High-quality PDF fits for Si, Ni, and Al2O3

Comparable results to traditional diffractometers

Validation of ARCS for quantitative PDF analysis

Abstract

The frst neutron powder diffraction based atomic pair distribution functions (PDFs) are reported from the new wide angular-range chopper spectrometer ARCS at the Spallation Neutron Source at Oak Ridge National Laboratory. The spectrometer was run in white-beam mode, with no Fermi chopper. The PDF patterns of Si, Ni, and Al2O3 were refined using the PDFfit method and the results compared to data collected at the NPDF diffractometer at Los Alamos National Laboratory. The resulting fits are of high quality demonstrating that quantitatively reliable powder diffraction data can be obtained from ARCS when operated in this configuration.