X-ray diffraction analysis is a method for studying the structural structure of substances. It is based on x-ray diffraction on special crystalline three-dimensional gratings. 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, along with neutron and electron diffraction, refers to diffraction methods for determining the structure of the substance under study.
It helps to study the atomic structure, 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 is worth noting that in the study of other substances, X-ray diffraction analysis requires crystals, which is an important but rather difficult task.
X-ray diffraction was discovered by Laue, the theoretical foundations were developed by Wulf and Bragg. Apply the discovered patterns in the role of analysis suggested Debye and Scherrer. I must say that at present, X-ray diffraction analysis remains one of the common methods for determining the structure of substances, since it is simple to execute 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 ever new techniques. So, at first they began to study the structure of matter using the functions of interatomic vectors, later direct methods for determining the crystal structure were developed. It is worth noting that the first substances that were investigated 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 identify important physicochemical properties of proteins, as well as to create the first DNA model.
Since the 50s, computer methods for collecting information that was obtained by x-ray structural analysis began to develop actively.
To date, synchrotrons are used. They are monochrome x-ray sources that are used to irradiate crystals. The most effective data devices are found in the multiwave anomalous dispersion method. It is worth noting that they are used only in state research centers. The 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.