A Team of Scientists From IKBFU and ESRF Found a New Gaphene Studying Method

Scientists from the European Synchrotron Radiation Facility (ESRF), together with scientists from the IKBFU Center for Coherent X-ray Optics for Megascience-class plants have proposed a new method of X-ray reflectometry on curved surfaces to study the graphene layer using a synchrotron radiation source.

Graphene is a light-strength material, which was obtained by Andrey Geim and Konstantin Novoselov using ordinary scotch tape. It was used to separate layers of graphene from a piece of graphite. Eventually they were able to obtain a carbon flake only one atom thick. Today, research on graphene is an important and urgent task. For example, some of the technologies under development include developing ultra-fast chargers, helping to regenerate tissues and bionic devices that can directly connect to your body's neurons. Graphene has three of the most useful properties: extreme toughness (100-300 times stronger than steel), high conductivity (the best known conductor of heat at room temperature, with an electrical current density six orders of magnitude greater than that of copper), and flexibility.

Commercial manufacturers of graphene have used a variety of ways to produce it. One of the most popular is the use of a substrate of molten copper, which is a catalyst and has a smooth surface. Since the properties of graphene greatly depend on the degree of its quality, it is necessary to monitor the growth parameters of the structure in real time. The classical method of studying the electron density profiles and interfaces of thin films with atomic accuracy is considered to be X-ray reflectometry. However, modern methodologies require high flatness, which becomes a challenge for naturally curved surfaces. This limitation applies especially to liquid metals because of their high surface tension.

Collaboration between scientists from the European Synchrotron Radiation Center and researchers at the IRRC made it possible to develop new approach to the study of curved surfaces. Experiments on X-ray reflectivity were conducted at the ID10 research station in Grenoble, France, using compound refractive lenses to focus X-rays. Scientists were able to obtain the refractometry curve from the curved surface in one shot, which allowed studying the structural characteristics of the graphene layer. The material was grown by chemical vapor deposition on molten copper and had a natural curvature in real time, without conducting the scanning procedure.