scholarly journals Symmetry-adapted pair distribution function analysis (SAPA): a novel approach to evaluating lattice dynamics and local distortions from total scattering data

2021 ◽  
Vol 54 (5) ◽  
pp. 1514-1520
Author(s):  
Tobias A. Bird ◽  
Anna Herlihy ◽  
Mark S. Senn

A novel symmetry-adapted pair distribution function analysis (SAPA) method for extracting information on local distortions from pair distribution function data is introduced. The implementation of SAPA is demonstrated in the TOPAS-Academic software using the freely available online software ISODISTORT, and scripts for converting the output from ISODISTORT to a SAPA input file for TOPAS are provided. Finally, two examples are provided to show how SAPA can evaluate the nature of both dynamic distortions in ScF3 and the distortions which act as an order parameter for the phase transitions in BaTiO3.

2020 ◽  
Vol 53 (3) ◽  
pp. 699-709 ◽  
Author(s):  
Chia-Hao Liu ◽  
Eric M. Janke ◽  
Ruipen Li ◽  
Pavol Juhás ◽  
Oleg Gang ◽  
...  

SASPDF, a method for characterizing the structure of nanoparticle assemblies (NPAs), is presented. The method is an extension of the atomic pair distribution function (PDF) analysis to the small-angle scattering (SAS) regime. The PDFgetS3 software package for computing the PDF from SAS data is also presented. An application of the SASPDF method to characterize structures of representative NPA samples with different levels of structural order is then demonstrated. The SASPDF method quantitatively yields information such as structure, disorder and crystallite sizes of ordered NPA samples. The method was also used to successfully model the data from a disordered NPA sample. The SASPDF method offers the possibility of more quantitative characterizations of NPA structures for a wide class of samples.


RSC Advances ◽  
2017 ◽  
Vol 7 (59) ◽  
pp. 37402-37411 ◽  
Author(s):  
U. P. Gawai ◽  
B. N. Dole

The atomic structures of nanowires were studied by X-ray atomic pair distribution function analysis and total synchrotron X-ray scattering data. A PDF method was used to describe a wurtzite and zinc-blended mixed phase model.


RSC Advances ◽  
2016 ◽  
Vol 6 (24) ◽  
pp. 19903-19909 ◽  
Author(s):  
M. P. Attfield ◽  
M. Feygenson ◽  
J. C. Neuefeind ◽  
T. E. Proffen ◽  
T. C. A. Lucas ◽  
...  

Combined Rietveld refinement and pair distribution function analysis of total neutron scattering data unveils the finer details of the negative thermal expansion mechanism of siliceous faujasite.


Nanoscale ◽  
2020 ◽  
Vol 12 (31) ◽  
pp. 16462-16473
Author(s):  
Margarita Rekhtina ◽  
Alessandro Dal Pozzo ◽  
Dragos Stoian ◽  
Andac Armutlulu ◽  
Felix Donat ◽  
...  

We use pair distribution function analysis of in situ total scattering data and complementary techniques to reveal how molten NaNO3 modifies the decomposition pathways of a hydrated magnesium carbonate to the formation of MgO.


2011 ◽  
Vol 44 (4) ◽  
pp. 788-797 ◽  
Author(s):  
Katharine Mullen ◽  
Igor Levin

Information on the size and structure of nanoparticles can be obtainedviaanalysis of the atomic pair distribution function (PDF), which is calculated as the Fourier transform of X-ray/neutron total scattering. The structural parameters are commonly extracted by fitting a model PDF calculated from atomic coordinates to the experimental data. This paper discusses procedures for minimizing systematic errors in PDF calculations for nanoparticles and also considers the effects of noise due to counting statistics in total scattering data used to obtain the PDF. The results presented here demonstrate that smoothing of statistical noise in reciprocal-space data can improve the precision of parameter estimates obtained from PDF analysis, facilitating identification of the correct model (from multiple plausible choices) from real-space PDF fits.


2011 ◽  
Vol 44 (2) ◽  
pp. 327-336 ◽  
Author(s):  
Katharine Page ◽  
Taylor C. Hood ◽  
Thomas Proffen ◽  
Reinhard B. Neder

High-energy X-ray and spallation neutron total scattering data provide information about each pair of atoms in a nanoparticle sample, allowing for quantitative whole-particle structural modeling based on pair distribution function analysis. The realization of this capability has been hindered by a lack of versatile tools for describing complex finite structures. Here, the implementation of whole-particle refinement for complete nanoparticle systems is described within two programs,DISCUSandDIFFEV, and the diverse capabilities they present are demonstrated. The build-up of internal atomic structure (including defects, chemical ordering and other types of disorder), and nanoparticle size, shape and architecture (including core–shell structures, surface relaxation and ligand capping), are demonstrated using the programDISCUS. The structure refinement of a complete nanoparticle system (4 nm Au particles with organic capping ligands at the surface), based on neutron pair distribution function data, is demonstrated usingDIFFEV, a program using a differential evolutionary algorithm to generate parameter values. These methods are a valuable addition to other probes appropriate for nanomaterials, adaptable to a diverse and complex set of materials systems, and extendable to additional data-set types.


2017 ◽  
Vol 50 (1) ◽  
pp. 14-21 ◽  
Author(s):  
Sylvain Grangeon ◽  
Alejandro Fernandez-Martinez ◽  
Alain Baronnet ◽  
Nicolas Marty ◽  
Agnieszka Poulain ◽  
...  

The structural evolution of nanocrystalline calcium silicate hydrate (C–S–H) as a function of its calcium to silicon (Ca/Si) ratio has been probed using qualitative and quantitative X-ray atomic pair distribution function analysis of synchrotron X-ray scattering data. Whatever the Ca/Si ratio, the C–S–H structure is similar to that of tobermorite. When the Ca/Si ratio increases from ∼0.6 to ∼1.2, Si wollastonite-like chains progressively depolymerize through preferential omission of Si bridging tetrahedra. When the Ca/Si ratio approaches ∼1.5, nanosheets of portlandite are detected in samples aged for 1 d, while microcrystalline portlandite is detected in samples aged for 1 year. High-resolution transmission electron microscopy imaging shows that the tobermorite-like structure is maintained to Ca/Si > 3.


2021 ◽  
Vol 75 (5) ◽  
pp. 368-375
Author(s):  
Kirsten M. Ø. Jensen

The development of new functional nanomaterials builds on an understanding of the intricate relation between material structure and properties. Only by knowing the atomic arrangement can the mechanisms responsible for material properties be elucidated and new materials and technologies developed. Nanomaterials challenge the crystallographic techniques often used for structure characterization, and the structure of many nanomaterials are therefore often assumed to be 'cut-outs' of the corresponding bulk material. Here, I will discuss how Pair Distribution Function (PDF) analysis of total scattering data can aid nanochemists in obtaining a structural understanding of nanoscale materials, focusing on examples from metal oxide chemistry.


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