X-ray diffraction analysis is a method for studying the structural structure of substances. It is based on the diffraction of an X-ray beam on special three-dimensional crystal lattices. The study uses waves whose length is approximately 1A, which corresponds to the size of the atom. It must be said that X-ray diffraction analysis, together with neutron and electron diffraction, refers to diffraction methods for determining the structure of the substance under study.
It helps to explore the atomic structure, the space groups of the unit cell, its size and shape, as well as the symmetry group of crystals. Using this technique, metals and their various alloys, organic and inorganic compounds, minerals, amorphous materials, liquids, and gases are studied. In some cases, X-ray diffraction analysis of proteins, nucleic acids and other substances is used.
This analysis helps to establish the atomic structure of crystalline materials, which have a well-defined structure and are a natural diffraction grating for X-rays. It should be noted that in the study of other substances, X-ray diffraction analysis requiresthe presence of crystals, which is an important but rather difficult task.
X-ray diffraction was discovered by Laue, the theoretical foundations were developed by Woolf and Bragg. Debye and Scherrer suggested using the discovered regularities in the role of analysis. It must be said that at present, X-ray diffraction analysis remains one of the most common methods for determining the structure of substances, since it is simple to perform and does not require significant material costs.
It allows you to explore different classes of substances, and the value of the information obtained determines the introduction of new techniques. So, at first they began to study the structure of matter using the function of interatomic vectors, later direct methods for determining the crystal structure were developed. It is worth noting that the first substances that were studied using X-rays were sodium and potassium chlorides.
The study of the spatial structure of proteins began in the 30s of the last century in the UK. The data obtained gave rise to molecular biology, which made it possible to reveal important physicochemical properties of proteins, as well as to create the first model of DNA.
Since the 1950s, computer methods for assembling information obtained from X-ray structural analysis began to develop actively.
Today, synchrotrons are used. They are monochrome X-ray sources that are used to irradiatecrystals. These devices are most effective when using the method of multiwave anomalous dispersion. It should be noted that they are used only in state scientific centers. Laboratories use a less powerful technique, which serves only to check the quality of crystals, as well as to obtain a rough analysis of substances.
