Standards Development

Scope

This part of IEC 62607 establishes a standardized method to determine the key control characteristic order parameter for graphene-based material and common carbon materials by X-ray diffraction (XRD) and transmission electron microscope (TEM).

The order parameter is analysed from two perspectives: z-axis and x-y-axis. In z-axis the order parameter is derived from the full width at half maxima (FWHM) of Miller index (002) in XRD spectrum. In x-y-axis, it is derived from the FWHM of Miller index (100) corresponding to diffraction patterns obtained by SAED (selected area electron diffraction) technique, which is routinely performed on most of TEM in the world.

– The method is applicable for graphene-based material and carbon material including graphite, expanded graphite, amorphous carbon, glassy carbon, the structures of which are clarified by other characterization techniques.

– Typical application areas are classifying graphene-based material and carbon-related materials and differentiating graphene from graphite for manufactures and downstream users.

Purpose

Graphite is composed of layers of carbon atoms just a single atom in thickness, known as graphene layers, to which it owes many of its remarkable properties. When the thickness of graphite flakes is reduced to just a few graphene layers, some of the material’s technologically most important characteristics are greatly enhanced. In other words, graphene is more than just graphite. Although graphene has a vast number of potential applications, a survey of commercially available graphene samples reveals that research could be undermined by the poor quality of the available material. Many highly priced graphene products from 60 producers consist mostly of graphite powder. Therefore, a lack of classification standards is creating a situation that downstream users are afraid to use graphene because they doubt whether the graphene is fake.

This IEC Technical Specification establishes a method for determining the order parameter of a carbon-related system. The order parameter can be analysed from z-axis and x-y-axis, respectively. The former can be derived from X-ray diffraction (XRD) spectra based on Bragg diffraction, and the latter can be derived from the diffraction patterns by selected area electron diffraction (SAED) technique, which is performed on transmission electron microscopy (TEM) with very high-resolution imaging.