Krasnoyarsk scientists for the first time predicted the possibility of obtaining stable magnetic MAX materials by changing their chemical composition. The new materials are ferromagnetic, highly magnetized and can be used at room temperature. In the future, this will make it possible to use such materials to create magnetic cooling and shielding devices. The results of the study are published in the Journal of Magnetism and Magnetic Materials.

MAX phases are layered materials consisting of three elements: M is a transition metal, A is one of the elements of the third and fourth groups of the periodic table, X is carbon or nitrogen. Of great interest is the combination of unique mechanical and magnetic properties of some of these materials. Attempts to synthesize such compounds do not stop. Failures in their synthesis are largely due to the instability of the obtained magnetic structures.

Scientists of the Federal Research Center "KSC SB RAS" for the first time predicted the possibility of obtaining stable magnetic MAX materials based on manganese and iron. In their work, the researchers proposed a new method for the synthesis of these compounds. It involves the replacement of elements in the M- or A-layers with magnetic atoms. This approach makes it possible to tune the magnetic properties of MAX phases by changing the chemical composition of their components.

One of the promising candidates to be included in the layered magnetic structures is the iron atom. The researchers replaced gallium with iron in a material composed of manganese, gallium and carbon. As a result, stable MAX phases were obtained with pronounced ferromagnetism and high magnetization. This also made it possible to increase the temperature at which the material does not lose its magnetic properties, and to bring it closer to room temperature, which means getting one step closer to using such materials under normal conditions.

“MAX phases with high magnetization and Curie temperatures close to room temperature are very promising. For example, they can be used for spintronics, magnetic storage and magnetic shielding, for magnetic cooling of server or data centers, and as permanent magnets for electric motors and wind turbines. The addition of iron atoms leads to the appearance of ferromagnetism in the MAX phases. Thus, we got an intriguing result: the magnetic alloy predicted by us is stable and exhibits pronounced ferromagnetic properties. Our discovery allows us to change the magnetic properties of the MAX phases and tune them by changing the chemical composition of the material,” said Oksana Draganyuk, junior researcher at the L.V. Kirensky Institute of Physics SB RAS.

The work was supported by the Russian Foundation for Basic Research, Krasnoyarsk Regional Science Foundation (No. 20-42-240004) and Megagrant of the RF Government for the creation of world-class laboratories (No. 075-15-2019-1886).

Megagrants are an initiative of the Government of the Russian Federation aimed at creating advanced laboratories in scientific organizations and universities with the involvement of world-famous scientists. In 2019, scientists from the Institute of Physics SB RAS received a mega-grant for the implementation of the project "Natural nanolayer materials promising for energy conversion". During three years of work, a group of specialists has been formed, engaged in modeling, development, creation and testing of new superconducting and magnetic MAX materials.

“The research work within the megagrant continues in the field of theoretical modeling of new possible magnetic MAX materials and their synthesis. The main achievement is that during three years, together with the German leader Michael Farle, we have assembled unique and necessary equipment for the synthesis of MAX structures. This can be found  nowhere else in the world. Now the assembly of the entire line has been completed, the equipment is being tested and will soon be put into operation in full. It will be possible to obtain samples and test previous theoretical calculations. The theoretical part is implemented in advance in order to understand how to make MAX-phases and which materials to use. We will select the best of them in terms of properties and parameters and conduct experimental studies on synthesized samples,” shared some of the interim results of the megagrant, Sergey Ovchinnikov, Doctor of Physical and Mathematical Sciences, Honored Scientist of the Russian Federation, head of the Magnetism direction at the L.V. Kirensky Institute of Physics SB RAS.