Scientists from Russia and Japan have figured out how to stabilize two-dimensional copper oxide (CuO) materials using graphene.
The materials under study are one of the main candidates for use in spintronics. It is quite possible that they will become part of quantum computers that are about to appear. The results of the study were published in The Journal of Physical Chemistry C.
Recently, a new class has been added to the family of two-dimensional materials - monolayers of transition metal oxides and carbides, to which a huge number of both theoretical and experimental studies have been devoted. Such materials are of interest to scientists because of their unusual rectangular atomic structure and chemical-physical properties.
It is extremely interesting for researchers to form a unique rectangular two-dimensional cell of copper oxide, which does not exist in a crystalline (3D) form, while most already known or recently discovered two-dimensional materials have a lattice type similar to the lattice of their crystalline (3D) counterparts. The practical application of promising monolayers is still limited by their low stability.
A team of scientists from MISiS, IBHF, Skoltech and the National Institute of Materials Science in Japan (NIMS), using experimental methods, managed to see 2D materials from copper oxide with an unusual crystal structure inside a matrix of two-layer graphene.
“It is important not only that a monolayer of copper oxide with a rectangular lattice can be stable under given conditions, but also that in our study we showed how the bonding and formation of a common boundary between copper oxide and a graphene nanopore leads to the stabilization of a small two-dimensional cluster of oxide copper with a rectangular lattice.
In contrast to a monolayer, in a small copper oxide cluster, edge effects (the presence of boundaries) exert a great influence on its stability, which leads to its curvature with the subsequent destruction of the flat 2D structure. Moreover, we have shown that in the case of pure copper, whose existence is impossible in the form of a flat cluster, its combination with two-layer graphene improves the stability of the 2D metal layer,”says Alexander Kvashnin, senior researcher at Skoltech.
The preference for the formation of a rectangular lattice of copper oxide in a bigraphene nanopore was shown by calculations using the evolutionary USPEX algorithm developed by Professor of Skoltech and MIPT Artem Oganov.
Studies of the physical properties of the obtained stable materials have shown that such 2D materials should be considered as candidates for use in the field of spintronics.