Bandwidth-controlled Mott transition in κ−(BEDT−TTF)2Cu[N(CN)2]BrxCl1−x\kappa-(BEDT-TTF)_2 Cu [N(CN)_2] Br_x Cl_{1-x} I. Optical studies of localized charge excitations

Infrared reflection measurements of the half-filled two-dimensional organic conductors $\kappa$-(BEDT-TTF)$_2$Cu[N(CN)$_{2}$]Br$_{x}$Cl$_{1-x}$ were performed as a function of temperature ($5 {\rm K}<T<300$ K) and Br-substitution ($x=0$, 40%, 73%, 85%, and 90%) in order to study the metal-insulator transition. We can distinguish absorption processes due to itinerant and localized charge carriers. The broad mid-infrared absorption has two contributions: transitions between the two Hubbard bands and intradimer excitations from the charges localized on the (BEDT-TTF)$_2$ dimer. Since the latter couple to intramolecular vibrations of BEDT-TTF, the analysis of both electronic and vibrational features provides a tool to disentangle these contributions and to follow their temperature and electronic-correlations dependence. Calculations based on the cluster model support our interpretation.Comment: 12 pages, 12 figure

Small Satellites “AIST” Constellation - Design, Construction and Program of Scientific and Technological Experiments

AbstractIn 2013 two small satellites of “AIST” series were launched into an orbit. This is the first joint project of Samara State Aerospace University (SSAU) and Space-Rocket Center (SRC) “Progress” which was crowned with full success. In the article the main tasks solved by spacecrafts are described, the design shape of the satellites is presented. The scientific equipment of small satellites, their principle of operation is described, some results of experiments are given.Work on creation of small satellites of “AIST” series became a starting point for high-quality growth of competences of SSAU and SRC “Progress” young specialists, and also for students who were engaged in the project. Besides, this project allowed to modernize essentially educational process in the field of space technics and technologies

Crystal and Magnetic State of Multiferroic Composites (x)MFe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt; + (1-x)BaTiO&lt;sub&gt;3&lt;/sub&gt;, M = Ni, Co

Multiferroic composites of (x)NiFe2O4 + (1-x)BaTiO3 with x = 0.2, 0.3 and 0.4 and (x)CoFe2O4 + (1-x)BaTiO3 with x = 0.2, and 0.4 have been synthesized by mixing NiFe2O4 (CoFe2O4) spinel and BaTiO3 piezoelectric. Distribution of Ni (Co) ions on 8a and 16d positions of spinel lattice (space group Fd-3m) is determined by neutron powder diffraction. Wave vector of magnetic structure of the spinel is k = 0. The dielectric permittivity of the composites was measured for the frequency range 102 – 105 Hz. At low frequencies the dielectric permittivity decreased from ~940 for x = 0.2 to ~360 for 0.4.</jats:p