In a study, a research group at Zhengzhou University in China led by Professor Qun Xu (D. Zhang, B. Gao, S. Xu, C. Niu) has expanded graphene into a composite material whose properties are enhanced by a strong reaction to magnetic fields. These properties open up a new avenue for spintronics, in which information transmission and storage depend not only on the movement of electrons but also on their magnetic properties.
The two-dimensional graphene consists of a single layer of carbon atoms on which the electrons can move freely on the surface, giving it a very high electrical conductivity. However, ferromagnetic properties are also required for a wide range of applications in electronics.
Hybrid graphene becomes ferromagnetic ...
In order to generate the ferromagnetism missing in graphene, the research team created a new hybrid material containing several layers of carbon atoms mixed with hydrogen and oxygen atoms. To do this, they exposed graphene to a carbon dioxide atmosphere at a pressure of over 100 atmospheres, whereby oxygen atoms were incorporated into the crystalline structure. The hydrogen atoms that were also incorporated came from hydrogen peroxide, which is a by-product of this process. The modification of the graphene structure led to the necessary changes in the electron properties, which became sensitive to an applied magnetic field. It is interesting to note that the processes take place at room temperature.
... and metal-free
An important aspect of this study is that, unlike alternative approaches, the researchers did not need any special metals to generate magnetism in the hybrid graphene, which means that future production would not cause any procurement problems or harmful environmental impacts. Prof. Xu predicted that the new approach of this study could be put into practice in three to five years, which would then be followed by scaling up to industrial mass production.
The study has been published as an open access version under the Creative Commons BY 4.0 Deed license and is available online at the following address: https://onlinelibrary.wiley.com/doi/full/10.1002/apxr.202300092 (accessed: 30 April 2024).
