Powder Xrd
Powder Xrd - Related Videos
08:14
Single Crystal and Powder X-ray Diffraction
0 Views •
2023
Source: Tamara M. Powers, Department of Chemistry, Texas A&M University X-ray crystallography is a technique that uses X-rays to study the structure of molecules. X-ray diffraction (XRD) experiments are routinely carried out with either single-crystal or powdered samples. Single-crystal XRD: Single-crystal XRD allows for absolute structure determination. With single-crystal XRD data, the exact atomic positions can be observed, and thus bond lengths and angles can be determined. This...
09:11
Porosimetry of a Silica Alumina Powder
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2023
Source: Kerry M. Dooley and Michael G. Benton, Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA Surface area and pore size distribution are attributes used by adsorbent and catalyst manufacturers and users to ensure quality control and to determine when products are at the end of their useful lives. The surface area of a porous solid is directly related to its adsorption capacity or catalytic activity. The pore size distribution of an adsorbent or catalyst is...
14:20
Absolute Quantum Yield Measurement of Powder Samples
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Cited by 16 •
2012
In this video we will demonstrate measuring and calculating absolute quantum yield and chromaticity coordinates directly in powder samples using the Hitachi F-7000 Quantum Yield Measuring System.
02:22
Cryomilling of Decellularized Tissue: A Technique to Obtain Fine Extracellular Matrix Powder
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2023
In this video, we present the protocol to obtain finely ground extracellular matrix powder from lyophilized decellularized tissue by cryomilling. The powdered ECM retains its biochemical composition and can be used for microcarrier synthesis.
11:25
In Situ Neutron Powder Diffraction Using Custom-made Lithium-ion Batteries
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Cited by 7 •
2014
We describe the design and construction of an electrochemical cell for the examination of electrode materials using in situ neutron powder diffraction (NPD). We briefly comment on alternate in situ NPD cell designs and discuss methods for the analysis of the corresponding in situ NPD data produced using this cell.
FAQs
The key diffraction condition is Bragg’s law: constructive interference occurs when the spacing between lattice planes matches the relationship required for the incident X-rays and diffraction angle. Because each crystalline arrangement contains characteristic plane spacings, changing the angle reveals where this condition is met. Those angular positions provide structural information for interpreting a powder pattern.
A detector records intensity as a function of diffraction angle. The resulting pattern contains angle-dependent features that reflect the crystalline material’s lattice structure and phases present. Because the complete pattern is characteristic of the crystal structure and phases present, chemists can use it for phase identification rather than relying on a single measurement.
Different polymorphs have different crystal structures, which can produce different lattice-plane spacings that satisfy Bragg’s law. Their resulting diffraction patterns may therefore distinguish one crystalline form from another. This capability supports polymorph detection and crystallinity assessment, especially when a material may occur in more than one crystalline form during chemical preparation or processing.
A typical measurement begins with a finely powdered sample. The sample is exposed to an incident X-ray beam while the detector records the diffracted intensity across diffraction angles. The resulting angle-dependent pattern is then interpreted through its characteristic relationship to crystal structure and phases, providing information for phase identification and other materials-characterization objectives.
Powder XRD can support phase identification, crystallinity assessment, polymorph detection, and lattice-parameter determination. It also provides a way to monitor structural changes during synthesis or processing because the measured diffraction pattern reflects the crystal structure and phases present. These outputs help chemists characterize materials beyond simply confirming that a sample is crystalline.
Chemists apply Powder XRD to materials used in catalysis, pharmaceuticals, minerals, and inorganic chemistry. In these areas, the technique can identify phases, distinguish polymorphs, assess crystallinity, determine lattice parameters, and follow structural changes during synthesis or processing. Its value lies in connecting measured diffraction patterns with the composition and structural state of crystalline materials.