Standardization

The National Physical Laboratory (NPL), in collaboration with international partners, have developed an ISO/IEC standard, ISO/TS 21356-1:2021, for measuring the structural properties of graphene, typically sold as powders or in a liquid dispersion. The ISO/IEC standard helps the supply chain to better define graphene materials (and distinguish them from other materials) and is based on methods developed with The University of Manchester in the NPL Good Practice Guide 145.

Over the last few years, graphene has started to move from the laboratory into real-world products such as cars and smartphones. However, there is still a barrier affecting the rate of its commercialization, namely, understanding the true properties of the material. There is not just one type of material, but many, each with different properties that need matching to the many different applications where graphene can provide an improvement.

Recent research by NPL, Oxford Instruments, Chalmers University and Graphensic has enabled the quantum Hall effect to be realized at both lower magnetic fields and higher temperatures, whilst still retaining part per billion accuracies.

The long-term collaboration between NPL, Chalmers University of Technology and Graphensic has resulted in a big advance in graphene samples. Epitaxial graphene (epigraphene) has been grown on silicon carbide and has better performance at higher temperatures and lower magnetic field than was previously possible. In practical terms, it has also removed the difficult process of fine-tuning the carrier density and means the ‘table-top’ system can be warmed up and cooled back down and the plateau stays where it is set with no user intervention.