An international group of scientists from NTU “MISiS” and the National Institute of Quantum Sciences and Radiology (Japan) have developed a material that will significantly increase the density of the recorded
information in storage devices such as solid state drives and flash drives. In addition, it has no overwriting limit, which will allow the introduction of devices from it in Big Data technology.
As we know, today is the traditional device in which information is transmitted by electric current. A promising alternative to electronics is spintronics,
where the control of information transfer is realized not only by the charge of electrons, but also by the current of spins – the intrinsic momentum of the electron momentum. In the spintronics of the device
work on the principle of magnetoresistive effect (magnetic resistance): there are three layers, the first and third of which are ferromagnetic, and the middle – non-magnetic. Going through this type of structure
“Sandwich”, electrons, depending on their spin, are scattered differently in the magnetized boundary layers, which affects the resulting resistance of the device. Detecting magnification or
reduction of this resistance, you can control the information using standard logic bits, 0 and 1.
Scientists have used a combination of graphene and semi-metallic Heisler alloy Co2FeGaGe (cobalt-iron-gallium-germanium). For the first time, Japanese colleagues were able to obtain a layer of graphene of atomic thickness
on a layer of semi-metallic ferromagnetic material and measure its properties.
As explained by the researchers, the feature used in the heterostructure of the alloy is manifested in one hundred percent spin polarization at the Fermi level, which is a prerequisite for use
it in spintron devices. In the investigated heterostructure, graphene does not interact with the magnetic material, which allows it to retain its unique conductive properties.
Earlier in the devices of magnetic memory did not use graphene: when trying to manufacture such layered materials, carbon atoms reacted with the magnetic layer, which led to its change
properties. Due to the careful selection of the composition of the Heisler alloy, as well as methods of its application, it was possible to create a more subtle pattern, compared to the previous analogues. This, in turn,
will significantly increase the capacity of magnetic memory devices without increasing their physical size.
The next steps of the scientists are scaling the experimental sample and further modifying the structure of the element.
SSD solid state drive, technology