Applications of an amorphous silicon-based area detector for high-resolution, high-sensitivity and fast time-resolved pair distribution function measurements

2007 ◽  
Vol 40 (3) ◽  
pp. 463-470 ◽  
Author(s):  
Peter J. Chupas ◽  
Karena W. Chapman ◽  
Peter L. Lee
Keyword(s):  
Distribution Function ◽  
Amorphous Silicon ◽  
Pair Distribution Function ◽  
High Sensitivity ◽  
High Energy ◽  
Scattering Data ◽  
Fast Time ◽  
Large Area ◽  
Nickel Metal ◽  
Time Resolved

The application of a large-area (41 × 41 cm, 2048 × 2048 or 1024 × 1024 pixel) high-sensitivity (detective quantum efficiency > 65%) fast-readout (up to 7.5 or 30 Hz) flat-panel detector based on an amorphous silicon array system to the collection of high-energy X-ray scattering data for quantitative pair distribution function (PDF) analysis is evaluated and discussed. Data were collected over a range of exposure times (0.13 s–7 min) for benchmark PDF samples: crystalline nickel metal and amorphous silica (SiO2). The high real-space resolution of the resultant PDFs (withQmaxup to ∼40 Å−1) and the high quality of fits to data [RNi(0.13s)= 10.5%,RNi(1.3s)= 6.3%] obtained in short measurement times indicate that this detector is well suited to studies of materials disorder. Further applications of the detector to locate weakly scattering H2molecules within the porous Prussian blue system, {\rm Mn}^{\rm II}_{\,3}[CoIII(CN)6]2·xH2, and to follow thein situreduction of PtIVO2to Pt0at 30 Hz, confirm the high sensitivity of the detector and demonstrate a new potential for fast time-resolved studies.

scholarly journals Time-resolved pair distribution function analysis of disordered materials on beamlines BL04B2 and BL08W at SPring-8

2018 ◽  
Vol 25 (6) ◽  
pp. 1627-1633 ◽  
Author(s):  
Koji Ohara ◽  
Satoshi Tominaka ◽  
Hiroki Yamada ◽  
Masakuni Takahashi ◽  
Hiroshi Yamaguchi ◽  
...  
Keyword(s):  
Distribution Function ◽  
Pair Distribution Function ◽  
Structural Changes ◽  
Function Analysis ◽  
Image Data ◽  
High Energy ◽  
Disordered Materials ◽  
X Rays ◽  
Two Dimensional ◽  
Time Resolved

A dedicated apparatus has been developed for studying structural changes in amorphous and disordered crystalline materials substantially in real time. The apparatus, which can be set up on beamlines BL04B2 and BL08W at SPring-8, mainly consists of a large two-dimensional flat-panel detector and high-energy X-rays, enabling total scattering measurements to be carried out for time-resolved pair distribution function (PDF) analysis in the temperature range from room temperature to 873 K at pressures of up to 20 bar. For successful time-resolved analysis, a newly developed program was used that can monitor and process two-dimensional image data simultaneously with the data collection. The use of time-resolved hardware and software is of great importance for obtaining a detailed understanding of the structural changes in disordered materials, as exemplified by the results of commissioned measurements carried out on both beamlines. Benchmark results obtained using amorphous silica and demonstration results for the observation of sulfide glass crystallization upon annealing are introduced.

In-situ Pair Distribution Function Study of the Growth of Supported Platinum Particles in Zeolite X

2014 ◽  
Vol 1712 ◽  
Author(s):  
Liliana M. Gámez ◽  
Oscar Resto ◽  
Maria M. Martinez-Inesta
Keyword(s):  
Distribution Function ◽  
Pair Distribution Function ◽  
High Energy ◽  
X Ray Diffraction ◽  
Zeolite X ◽  
Time Resolved ◽  
Supported Platinum ◽  
Platinum Particles ◽  
Dehydrogenation Reactions

ABSTRACTPlatinum particles supported in zeolites are used as catalysts for hydrogenation/ dehydrogenation reactions. In this study in situ high energy synchrotron X-ray diffraction was used to study the Pt particle formation under calcination and reduction conditions using time resolved pair distribution function (PDF). Because these particles grow inside the pores of zeolite X, PDF is able to give insight to unique information at the short and medium interatomic distance range that cannot be readily obtained with other techniques. Among the information obtained are the Pt atom interactions during calcination and the evolvement of the Pt particle sizes and average Pt-Pt distances during reduction.

scholarly journals Demonstration of thin film pair distribution function analysis (tfPDF) for the study of local structure in amorphous and crystalline thin films

IUCrJ ◽  
2015 ◽  
Vol 2 (5) ◽  
pp. 481-489 ◽  
Author(s):  
Kirsten M. Ø. Jensen ◽  
Anders B. Blichfeld ◽  
Sage R. Bauers ◽  
Suzannah R. Wood ◽  
Eric Dooryhée ◽  
...  
Keyword(s):  
Thin Films ◽  
Distribution Function ◽  
Structure Analysis ◽  
Local Structure ◽  
Pair Distribution Function ◽  
High Energy ◽  
Scattering Data ◽  
X Rays ◽  
Amorphous Precursor ◽  
Total Scattering

By means of normal-incidence, high-flux and high-energy X-rays, total scattering data for pair distribution function (PDF) analysis have been obtained from thin films (tf), suitable for local structure analysis. By using amorphous substrates as support for the films, the standard Rapid Acquisition PDF setup can be applied and the scattering signal from the film can be isolated from the total scattering data through subtraction of an independently measured background signal. No angular corrections to the data are needed, as would be the case for grazing incidence measurements. The `tfPDF' method is illustrated through studies of as-deposited (i.e.amorphous) and crystalline FeSb3films, where the local structure analysis gives insight into the stabilization of the metastable skutterudite FeSb3phase. The films were prepared by depositing ultra-thin alternating layers of Fe and Sb, which interdiffuse and after annealing crystallize to form the FeSb3structure. The tfPDF data show that the amorphous precursor phase consists of corner-sharing FeSb6octahedra with motifs highly resembling the local structure in crystalline FeSb3. Analysis of the amorphous structure allows the prediction of whether the final crystalline product will form the FeSb3phase with or without excess Sb present. The study thus illustrates how analysis of the local structure in amorphous precursor films can help to understand crystallization processes of metastable phases and opens for a range of new local structure studies of thin films.

Building and refining complete nanoparticle structures with total scattering data

2011 ◽  
Vol 44 (2) ◽  
pp. 327-336 ◽  
Author(s):  
Katharine Page ◽  
Taylor C. Hood ◽  
Thomas Proffen ◽  
Reinhard B. Neder
Keyword(s):  
Distribution Function ◽  
Pair Distribution Function ◽  
Function Analysis ◽  
Structure Refinement ◽  
High Energy ◽  
Scattering Data ◽  
Surface Relaxation ◽  
Data Set ◽  
Total Scattering ◽  
Differential Evolutionary Algorithm

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.

scholarly journals Effects of Crystal Morphology on the Hot-Carrier Dynamics in Mixed-Cation Hybrid Lead Halide Perovskites

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 708
Author(s):  
Daniele Catone ◽  
Giuseppe Ammirati ◽  
Patrick O’Keeffe ◽  
Faustino Martelli ◽  
Lorenzo Di Mario ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Carrier Dynamics ◽  
Large Area ◽  
Photovoltaic Properties ◽  
Time Resolved ◽  
Hot Carrier ◽  
Mixed Cation ◽  
Small Crystals ◽  
Characterization Of Materials ◽  
Lead Halide

Ultrafast pump-probe spectroscopies have proved to be an important tool for the investigation of charge carriers dynamics in perovskite materials providing crucial information on the dynamics of the excited carriers, and fundamental in the development of new devices with tailored photovoltaic properties. Fast transient absorbance spectroscopy on mixed-cation hybrid lead halide perovskite samples was used to investigate how the dimensions and the morphology of the perovskite crystals embedded in the capping (large crystals) and mesoporous (small crystals) layers affect the hot-carrier dynamics in the first hundreds of femtoseconds as a function of the excitation energy. The comparative study between samples with perovskite deposited on substrates with and without the mesoporous layer has shown how the small crystals preserve the temperature of the carriers for a longer period after the excitation than the large crystals. This study showed how the high sensitivity of the time-resolved spectroscopies in discriminating the transient response due to the different morphology of the crystals embedded in the layers of the same sample can be applied in the general characterization of materials to be used in solar cell devices and large area modules, providing further and valuable information for the optimization and enhancement of stability and efficiency in the power conversion of new perovskite-based devices.

scholarly journals SASPDF: pair distribution function analysis of nanoparticle assemblies from small-angle scattering data

2020 ◽  
Vol 53 (3) ◽  
pp. 699-709 ◽  
Author(s):  
Chia-Hao Liu ◽  
Eric M. Janke ◽  
Ruipen Li ◽  
Pavol Juhás ◽  
Oleg Gang ◽  
...  
Keyword(s):  
Distribution Function ◽  
Small Angle ◽  
Pair Distribution Function ◽  
Function Analysis ◽  
Small Angle Scattering ◽  
Scattering Data ◽  
Nanoparticle Assemblies ◽  
Angle Scattering ◽  
Pdf Analysis ◽  
Crystallite Sizes

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.

Sign in / Sign up

Export Citation Format

Share Document