Determining the Size of Mosaic Blocks and Anisometry of the Flakes of Artificial Graphite by Magnetoresistance

Abstract: The article presents the results of the mathematical modeling of the flow of the electric current in a lamellar graphite polycrystal in a magnetic field. In contrast to the simple model, which takes into account only the contact resistance between the flakes, this model also takes into account the ohmic resistance along and across the layers of graphite based on the chain model of the flow of the electric current in a graphite polycrystal. As a result, a formula with refined correction coefficients is obtained, which allows us to choose polycrystal parameters for calculating the temperature dependence of resistivity and magnetoresistance. A comparison is made with a simple model that takes into account only contact resistance, the difference is up to 50% from the previous estimate. The difference is explained by the peculiarities of the connection of crystallites in a polycrystal. This allows analyzing the size of the crystallites and their connections in artificial graphite based on its electrophysical properties. © 2020, Pleiades Publishing, Ltd.