Spintronics is a field of science which studies application of the properties of the spin (magnetic moment) of particles, such as electrons, in creation of new devices and instruments. By the beginning of the XXI century, it became clear that the most suitable new materials for spintronics could be not only ideal crystals, but crystals containing vacancies.
The vacancies are defects in the crystal lattice. They can be created by means of various processes, such as irradiation, heating or by pressure. Their presence can significantly affect the properties of crystals: to change hardness, electrical conductivity, optical properties, etc.
In particular, silicon vacancy in silicon carbide is considered to be promising. The energy of formation of silicon vacancies in silicon carbide is extremely high. Therefore they are currently obtained by irradiation with beams of high-energy particles. But there are very few vacancies with the necessary properties obtained by irradiation, about 108-1012 cm-3.
«The Laboratory of Structural and Phase Transformations of the Institute for Problems in Mechanical Engineering ofRAS under the leadership of Sergey Kukushkin, the Head of the Lab., Professor, was the first to develop a technology that allows for obtaining silicon vacancies in SiC in the right amount,» said Andrey Osipov, Chief Researcher in the Laboratory of Structural and Phase Transformations in Condensed Media of IPMash RAS.
The new technology developed at IPMash RAS creates silicon vacancies in silicon instead of silicon carbide initially, that is not only easier, but also more efficient. Then the upper part of the silicon with vacancies turns into a silicon carbide layer due to a chemical reaction. The concentration of silicon vacancies with this technology is many orders of magnitude higher than with irradiation, and their distribution over the surface is more uniform. This new material provides a high density of spin-polarized current which can be used for commercial purposes.
Earlier, the scientists of the Institute for Problems in Mechanical Engineering (IPMash) of RAS created the first Russian technology for producing silicon carbide, a crystalline material for microelectronics which characteristics surpass silicon used at present. The technology is simple and is many times cheaper than the existing foreign technologies.