1,039 research outputs found

    Infrared spectra of some sulfides and their analogs of binary composition in the long-wave region

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    The far infrared spectra (500-60/cm) of some simple sulfides and their analogs were studied. In all, 22 minerals with different structure types were investigated, out of which 14 are sulfides (galena, alabandite, pyrrhotite, sphalerite, wurtzite, cinnabar, realgar, orpiment, getchelite antimonite, molybdenite, pyrite, marcasite and heazlewoodite) 6 arsenides (niccolite, domeykite, arsenopyrite, lollingite, rammelsbergite and skutterudite), one telluride (tetradymite) and native arsenic. The main bands of infrared absorption spectra of the minerals are compared with the relative strength of the interatomic bonds and their interpretation is given

    Strategic directions of transport and logistics to ensure the implementation of new industrialization processes

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    Ensuring the processes of industrialization of the modern economy requires the formation of an efficient transport and logistics infrastructure. The solution of this task is carried out using the tools of strategic management, in particular the formation of strategic goals. The article presents the strategic goals and the corresponding strategic measures in the field of ensuring the availability and quality of transport and logistics services in the field of freight traffic at the level of the needs of the development of the economy of the Sverdlovsk region. © Published under licence by IOP Publishing Ltd

    Modification of magnetic and transport properties of manganite layers in Au/La_0.67Sr_0.33MnO_3/SrTiO_3 interfaces

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    The effect of gold capping on magnetic and transport properties of optimally doped manganite thin films is studied. An extraordinary suppression of conductivity and magnetic properties occurs in epitaxial (001) La_0.67Sr_0.33MnO_3 (LSMO) films grown on SrTiO_3 upon deposition of 2 nm of Au: in the case of ultrathin films of LSMO (4 nm thick) the resistivity increases by four orders of magnitude while the Curie temperature decreases by 180 K. Zero-field 55Mn nuclear magnetic resonance reveals a significant reduction of ferromagnetic double-exchange mechanism in manganite films upon the gold capping. We find evidence for the formation of a 1.9-nm thick magnetic "dead-layer" at the Au/LSMO interface, associated with the creation of interfacial non double-exchange insulating phases.Comment: 4 figure

    Kondo Insulator to Semimetal Transformation Tuned by Spin-Orbit Coupling

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    Recent theoretical studies of topologically nontrivial electronic states in Kondo insulators have pointed to the importance of spin-orbit coupling (SOC) for stabilizing these states. However, systematic experimental studies that tune the SOC parameter λSOC\lambda_{\rm{SOC}} in Kondo insulators remain elusive. The main reason is that variations of (chemical) pressure or doping strongly influence the Kondo coupling JKJ_{\text{K}} and the chemical potential μ\mu -- both essential parameters determining the ground state of the material -- and thus possible λSOC\lambda_{\rm{SOC}} tuning effects have remained unnoticed. Here we present the successful growth of the substitution series Ce3_3Bi4_4(Pt1x_{1-x}Pdx_x)3_3 (0x10 \le x \le 1) of the archetypal (noncentrosymmetric) Kondo insulator Ce3_3Bi4_4Pt3_3. The Pt-Pd substitution is isostructural, isoelectronic, and isosize, and therefore likely to leave JKJ_{\text{K}} and μ\mu essentially unchanged. By contrast, the large mass difference between the 5d5d element Pt and the 4d4d element Pd leads to a large difference in λSOC\lambda_{\rm{SOC}}, which thus is the dominating tuning parameter in the series. Surprisingly, with increasing xx (decreasing λSOC\lambda_{\rm{SOC}}), we observe a Kondo insulator to semimetal transition, demonstrating an unprecedented drastic influence of the SOC. The fully substituted end compound Ce3_3Bi4_4Pd3_3 shows thermodynamic signatures of a recently predicted Weyl-Kondo semimetal.Comment: 6 pages, 5 figures plus Supplemental Materia

    Beyond Moore's technologies: operation principles of a superconductor alternative

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    The predictions of Moore's law are considered by experts to be valid until 2020 giving rise to "post-Moore's" technologies afterwards. Energy efficiency is one of the major challenges in high-performance computing that should be answered. Superconductor digital technology is a promising post-Moore's alternative for the development of supercomputers. In this paper, we consider operation principles of an energy-efficient superconductor logic and memory circuits with a short retrospective review of their evolution. We analyze their shortcomings in respect to computer circuits design. Possible ways of further research are outlined.Comment: OPEN ACCES
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