Use of Natural Flake Graphite in the Calibration of Instrumental Research Methods

Abstract

The size of mosaic blocks along the graphite layers (that is, the average diameter of crystallites in the basal plane) was determined by two methods for specially made model materials based on narrow fractions of flake graphite powders and milled pyrographite with lamellar particles. The first method consisted in the calculation of mosaic block sizes from a minimum of the temperature dependence of electrical conductivity using an empirical law according to Mason; the second method based on mathematical modeling used the values of the magnetoresistance of carbon materials at temperatures of 80 and 300 K. The correspondence between the sizes of mosaic blocks calculated by these methods along the graphite layers in the considered materials was shown. A correction for the lamellar shape of graphite crystallites was determined to calculate the sizes of mosaic blocks in the direction perpendicular to the graphite layers from the 002 peak broadening in the diffraction pattern.