Jr., Reynolds, 1989, X-ray diffraction and identification and analysis of clay minerals : London, Oxford University Press, p. Dauger, 2001, Modelling of line profile asymmetry caused by axial divergence in powder diffraction : Journal of Applied Crystallography, v. Champion, 1991, The I/S-to-illite reaction in the late stage diagenesis : American Journal of Science, v. Visser, 1986, Applications of total pattern fitting to a study of crystallite size and strain in zinc oxide powder : Powder Diffraction, v. Alexander, 1974, X-ray diffraction procedures for polycrystalline and amorphous materials : New York, John Wiley & Sons, p. phosphorus sorption by 11 Puerto Rican soils : Soil Sci. C., 1981, X-ray diffraction line profile analysis vs. Nichols, 1990, Problems in the derivation of d-values from experimental digital XRD patterns : Advances in X-Ray Analysis, v. Toraya, 2000, Extended pseudo-Voigt function for approximating the Voigt profile : Journal of Applied Crystallography, v. Johnson, 1978, Crystallinity and crystallite size measurement in polyamide and polyester fibres : Polymer, v. Mahlmann, 1999, Alpine metamorphism of the central Alps: Sc HWeizerische Mineralogische und Petrographische Mitteilungen : v. Vogels, 1982, Use of the Voigt function in a single-line method for the analysis of X-ray diffraction line broadening : Journal of Applied Crystallography, v. Aladekomo, 1995, Diffraction by diffusely scattering materials of high transparency : Journal of Applied Crystallography, v. Ledbetter, 1993, Voigt-function modeling in Fourier analysis of size- and strain-broadened X-ray diffraction peaks : Journal of Applied Crystallography, v. Since all physical objects have wave-like properties at the atomic level, diffraction can be studied in accordance with the principles of quantum mechanics.Balzar, D. Similar effects occur when light waves travel through a medium with a varying refractive index, resulting in a spectrum of color or a distorted image. Ever notice how the outer edges do not appear solid, but slightly fuzzy instead? This occurs as a result of light bending slightly as it passes around the edge of an object, again, consistent with the behavior of a wave. Young, and those who repeated the experiment, found that interference waves resulted, meaning that two propagation waves occurred which then began to interfere with one another.Ī more common example comes to us in the form of shadows. The experiment was even more interesting when a second slit was cut into the screen (hence the name double-slit). Instead of appearing in the same relative shape as the aperture, the light appeared to be diffracting, implying that it was made up of waves. The results were interesting, to say the least. light of a single color) through an aperture (in this case, a wall with a horizontal slits cut in it) and measured the results on a screen located on the other side. In this experiment, Young shone a monochromatic light source (i.e. One such physicist who observed this at work was Thomas Young (1773 – 1829), an English polymath who is credited devised the double-slit experiment. It had long been understood that this is what happens when a wave encounters an obstacle, and by the 17th and 18th centuries, this behavior was observed through experiments involving light. So you can imagine how confounded they were when, in the course of performing experiments, they discovered that it exhibited the behavior of both a particle and a wave! This rather unique behavior, the ability of light to behave as a wave, even though it is made up of tiny particles, is known as the Diffraction of Light.īy definition, diffraction refers to the apparent bending of waves around small obstacles and the spreading out of waves past small openings. However, with the advent of quantum physics, scientists came to realize that photons, a tiny elementary particle responsible for all forms of electromagnetic radiation, was in fact the source. Initially, and in accordance with classic physics, light was thought to be a wave, an indefinable form of energy that simply flowed from a heated source. For some time, the behavior of light has baffled scientists.
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