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Spintronics
(spin-based electronics), also known as magnetoelectronics, is an emergent
technology making use of the electrons spin as well as of their charge. The
search of new materials for spintronics is one of the main problems facing
solid state physics and magnetism. Due to the features of a crystal
structure, layered intercalated materials can be of great interest for
spintronics. In this series of compounds the intercalation and cation
substitution allow to create the substances with the electrical resistivity
and magnetization controlled by chemical composition of a matrix. The
phenomenon of the colossal magnetoresistance (CMR) was recently revealed in
this class of substances (for instance, CMR of CuVxCr1-xS2 reaches - 40% in
the magnetic field of 1 Tesla). The purpose of the present research is
synthesis and study of new layered materials with colossal magnetoresistance
capable to simplify the technology of fabrication of the multilayer
structures. In the framework of this grant the new layered sulfides
CuMexCr1-xS2 (Me = V, Fe; 0 < X < 0.3) and oxides MexPb3Mn7-xO15 (Me= Bi, Sr,
Ru, Fe, Ga, Ti) will be synthesized and the complex study of their physical
properties, as well as crystal, magnetic and electron structure will be
carried out by state-of-the-art crystal investigation methods (for example,
X-ray structural analysis, neutron diffraction, X-ray electronic
spectroscopy).
Continued below .......
The totality of the results on electric, magnetostatic, magnetodynamic and
galvanomagnetic properties in combination with data on crystal, magnetic and
electronic structures of solid solutions of polycrystalline samples and
single crystals will allow us to clarify the basic regularities of
percolation and spin-dependent effects in layered intercalated structures
and to give recommendations on the creation of new materials with the
required physicotechnical parameters for spintronics. Therefore, the
objectives of this proposal are to get information on the - crystal,
electronic and magnetic structure of the new layered materials; -
possibility of control of electron transport and physical properties of
these materials by cation substitution and magnetic field; - main features
and peculiarities of colossal magnetoresistance in intercalated and layered
structures; - role of the degree of lattice ordering, stoichiometry and
local neighborhood in the formation of compounds with high CMR values. The
result of the research work will be phase diagrams describing the behavior
of magnetic, electric and structural properties of the synthesized materials
depending on the cation substitution degree, temperature and magnetic field.
As we are making a strong effort on theoretical understanding of our
experimental results, we expect not only to specify our systems
investigated, but also to give essential input for the search of new
materials.
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