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The use of computational methods for the powder X-ray diffraction data analysis is now generalized. It typically compares the experimental data to the simulated diffractogram of a model structure, taking into account the instrumental parameters, and refines the structural or microstructural parameters of the model using least squares based ...
The Scherrer equation, in X-ray diffraction and crystallography, is a formula that relates the size of sub-micrometre crystallites in a solid to the broadening of a peak in a diffraction pattern. It is often referred to, incorrectly, as a formula for particle size measurement or analysis. It is named after Paul Scherrer.
Copper(II) chloride is used as a catalyst in a variety of processes that produce chlorine by oxychlorination. The Deacon process takes place at about 400 to 450 °C in the presence of a copper chloride: [8] 4 HCl + O 2 → 2 Cl 2 + 2 H 2 O. Copper(II) chloride catalyzes the chlorination in the production of vinyl chloride and dichloromethane. [8]
Laboratory X-ray diffraction equipment relies on the use of an X-ray tube, which is used to produce the X-rays. The most commonly used laboratory X-ray tube uses a copper anode, but cobalt and molybdenum are also popular. The wavelength in nm varies for each source. The table below shows these wavelengths, determined by Bearden [14] (all values ...
X-ray diffraction is a generic term for phenomena associated with changes in the direction of X-ray beams due to interactions with the electrons around atoms. It occurs due to elastic scattering , when there is no change in the energy of the waves.
X-ray diffraction is a non destructive method of characterization of solid materials. When X-rays are directed at solids they scatter in predictable patterns based on the internal structure of the solid. A crystalline solid consists of regularly spaced atoms (electrons) that can be described by imaginary planes.
Here () is the reflectivity, = /, is the X-ray wavelength (e.g. copper's K-alpha peak at 0.154056 nm), is the density deep within the material and is the angle of incidence. The Fresnel reflectivity, R F ( Q ) {\displaystyle R_{F}(Q)} , in the limit of small angles where polarization can be neglected, is given by:
which is a Lorentzian or Cauchy function, of FWHM / = (/) /, i.e., the FWHM increases as the square of the order of peak, and so as the square of the wave vector at the peak. Finally, the product of the peak height and the FWHM is constant and equals 4 / a {\displaystyle 4/a} , in the q σ 2 ≪ 1 {\displaystyle q\sigma _{2}\ll 1} limit.