Relationship between the Poisson's ratio and changes in the unit cell parameters of the body-centered crystal lattice of iron in the region of elastic deformation.

At present, experimental studies often do not coincide, and sometimes contradict the mathematical models used to evaluate the physical process during the experiment. Sometimes during the experiment, it is possible to establish new data. Thus, the discovery of monatomic two-dimensional materials not only established the existence of such materials, but also refined the theory of the crystal structure of materials by O. Bravais, which was a "dogma" for almost two centuries. Mathematical models contribute to the development of scientific thought and experimental research; however, the "priority" of research should still be the physical representation of the mechanism of the process. At the same time, the model of the physical process should be applicable not only in this particular study, but also in related areas of research, which will make it possible to establish a single mechanism existing in nature. To do this, it is necessary to analyze between the "separate" concepts and equations existing in science in order to find common patterns. In this paper, it is proposed to establish the relationship between the equation that determines the Poisson's ratio ν and the structure of the crystal lattice in the form of the size parameter of the unit crystal cell of the crystal - a. We will establish this relationship for the elementary cell of iron, which, according to the theory of O. Brave, has a body-centered cubic crystal lattice. [ABSTRACT FROM AUTHOR]