Offers of high school on participation in joint researches with the European universities within the limits of thematic priorities of the Seventh frame program of scientifically-technological development of EU
Nanosciences, Nanotechnologies, Materials and New Production Technologies - NMP
Call Identifier: FP7-2008-Energy-NMP-2
NMP-2008-2.1-2, Area: The features of electronic, lattice, magnetic subsystems of nanostructured diborides of rare-earth elements
The brief description of the project
Diborides of rare-earth elements (RB2) is crystallized in hexagonal structure which consists of alternating close-packed layers of metal atoms and hexagonal layers of boron atoms. Such structure under certain conditions may promote a formation of two-layer nano-tubes consisting of coaxial cylindrical layers of metal and boron atoms. Until recently there is no reliable method of synthesis of single-phase rare-earth diborides, their properties practically are not investigated. The majority of rare-earth diborides at low temperatures are ferromagnetics (YbB2 is an antiferromagnetic), have metal type of electric conductivity.
Samples of diborides are supposed to be synthesized in inertial atmosphere at high temperatures from elements via the intermediate hydride phase, and also with application of high pressures.
The purpose of investigation is development of technologies of synthesis of RB2, determination of laws of changes of magnetic, electronic, lattice properties of RB2 with change of diboride composition and temperatures on the basis of the experimental studying of temperature dependences of heat capacity, parameters of crystal lattice, magnetic, kinetic, electrical, including thermoelectric properties of diborides in a wide temperature range (0,4 - 300 K).
Technology of synthesis of pure phases of rare-earth diborides.
Laws of temperature changes of heat capacity, thermal expansion coefficients, mean-square displacements of atoms in sites of crystal lattice of diborides at the temperatures 0.4-300 K.
Values of characteristic temperatures, density of electron states at Fermi level, parameters of exchange interaction of RB2, laws of changes of the mentioned characteristics with change of rare-earth element number in Periodic system.
V.V. Novikov, A.V. Matovnikov. Low-temperature Heat Capacity of Dysprosium Diboride. 9-th European Symposium on Thermoanalysis and Calorimetry, 27 – 31 August 2006, Krakov, Poland;
A.V.Matovnikov. Synthesis and thermodynamic properties of some diborides of rare-earth elements. Microelectronics and computer science-2006. The 13th All-Russia interuniversity scientific and technical conference of students and post-graduate students: Theses of reports. Moscow.: Moscow institute of electronic technique, 2006. - 404 p.;
V.V.Novikov. The lattice heat capacity of binary compounds in approach of three-dimensional Debye sublattices. Zhurnal fizicheskoj khimii, 2006, v.80 N.9, p. 1645-1649;
V.V.Novikov, A.V.Matovnikov. Heat capacity, enthalpy, entropy and Gibbs energy of terbium diboride on the calorimeter data in the range 5 - 300 K. Zhurnal fizicheskoj khimii, 2007, N. 4, p. 762-765;
V.V.Novikov, A.V.Matovnikov. Components of the low-temperature heat capacity and the magnetic phase transition of terbium diboride TbB2. Neorganicheskie materiali, 2008, v.44, N.1, p. 1-5;
V.V.Novikov, A.V.Matovnikov, T.A.Chukina, A.A.Sidorov, E.A.Kul"chenkov. The low-temperature heat capacity and crystal lattice dynamics of yttrium diboride. Fizika tverdogo tela, 2007, v.49, N.11, 1941-1944;
V.V. Novikov, A.V. Matovnikov. Low-temperature Heat Capacity of Dysprosium Diboride. Journal of Thermoanalysis and Calorimetry, 2007, v.88, № 2, p. 597-599;
V.V. Novikov. The Phonon Heat Capacity of Rare Earth Diborides: the Approximation of Interacting Sublattices. European Symposium on Boron and Related Compounds Euroboron 4, 2-6 September 2007, Bremen: Theses of reports, p. 129.
V.V. Novikov, A.V. Matovnikov. Synthesis, thermodynamic and magnetic properties of holmium diboride HoB2 in a temperature interval 2 – 300 K. European Symposium on Boron and Related Compounds Euroboron 4, 2-6 September 2007, Bremen: Theses of reports, p. 121.
V.V. Novikov, T.A. Chukina. X-ray investigation of lattice dynamics of dysprosium diboride at the temperatures of 4.2 – 300 K. European Symposium on Boron and Related Compounds Euroboron 4, 2-6 September 2007, Bremen: Theses of reports, p. 162.