Valence of cerium ions in selected ternary compounds from the system Ce-Rh-Sn

Over the last years, intermetallic compounds from the system Ce–Rh–Sn have attracted a considerable attention owing to a rich variety of strongly correlated electron phenomena they exhibit. CeRhSn2, Ce5Rh4Sn10, Ce2Rh3Sn5 and Ce3Rh4Sn13 are magnetically ordered heavy fermion systems [1-5]. Interestingly, for Ce3+xRh4Sn13-x (0.2<x<0.6) no sign of Kondo effect and long range magnetic order was found down to the temperature of 0.4 K [5]. In turn, CeRhSn shows non-Fermi liquid-type thermodynamic and transport properties at low temperatures [6-7] accompanied by an intermediate valence state of the Ce ions. Further, for CeRhSn, CeRhSn2 and CeRh2Sn4 spin fluctuations due to the Rh 4d electrons were also suggested [1,7-8]. The possible coexistence of magnetic phenomena originating from Ce and Rh makes the unequivocal interpretation of experimental data for these compounds very difficult. Consequently, a detailed understanding of the very complex physical properties/behavior requires the use of a broad spectrum of experimental methods, including extended thermodynamic and transport measurements as well as careful investigations of electronic structure. For these systems the full characterization of Ce 4f states in regard to their occupancy, localization in a conduction band and hybridization with the other valence band states is crucial for an unambiguous determination of ground state properties and the low energy excitations. Thus, X-ray absorption spectroscopy (XAS) is here of great use as a bulk probe which is highly sensitive on chemical states of elements. Furthermore, absorption measurements at the Ce LIII edge results in spectra with minimized lifetime broadening, largely unaffected by complicated many-electron final state effects. These spectra can be used to estimate the numbers for the fractional valence of Ce which originates from the strong hybridization between the Ce 4f and the other valence band states related to the valence fluctuation phenomena and/or to the formation of covalent bonds

Ukrainian Soviet Family: Formative stages

The purpose of the article: is to determine the peculiarities of the formation of family policy of the Soviet government and the co-existence of private and public in the household of Ukrainian families during the existence of the Soviet system. Research methods: comparative method, method of analogy, analysis and synthesis method, method induction and deduction were used in the course of the research. The results of the research. A comparative analysis of the peculiarities of the existence of Soviet families at different stages of the Soviet period was conducted. The parallels were drawn between the traditional Ukrainian family in the pre-revolutionary period and family innovations in the Soviet period. Practical implication. A generalized description of the position of the Ukrainians as a common element of the Soviet people under the Soviet system is provided. Value/Originality. The role of statistics alongside memories for a better reflection of the daily life of the Ukrainian Soviet family under the conditions of double standards of Soviet society is shown for the first time

Superconducting gap structure of the skutterudite LaPt4Ge12 probed by specific heat and thermal transport

We investigated the superconducting order parameter of the filled skutterudite LaPt4Ge12, with a transition temperature of Tc = 8.3 K. To this end, we performed temperature and magnetic-field dependent specific-heat and thermal-conductivity measurements. All data are compatible with a single superconducting s-wave gap. However, a multiband scenario cannot be ruled out. The results are discussed in the context of previous studies on the substitution series Pr1-xLaxPt4Ge12. They suggest compatible order parameters for the two end compounds LaPt4Ge12 and PrPt4Ge12. This is not consistent with a single s-wave gap in LaPt4Ge12 considering previous reports of unconventional and/or multiband superconductivity in PrPt4Ge12.Comment: 8 pages, 4 figure

Визначення техніко-економічних параметрів транспортера-сепаратора коренеплодів при їх переміщенні криволінійною трасою

The results of theoretical and experimental study of the process of root crops carrying by a conveyer-separator of a three-row trailed root crop harvester whose rubber belt with rods is equipped with scrapers and has a sign-variable direction of transportation to minimize the machine length have been described in the article. Some analytical dependencies describing the impact of design and kinematic parameters of the conveyer-separator on the root crops motion pattern have been given and analysed. The results of the research including the key factors identification affecting the process of root crops transportation on the curvilinear path between the conveyer-separator members are presented in the experimental part. The theoretical and experimental studies have been compared and the boundaries of the most efficient design and kinematic parameters choice of the conveyer-separator under discussion have been suggested.У статті наведені результати теоретичних і експериментальних досліджень процесу переміщення коренеплодів транспортером-сепаратором трирядної причіпної коренезбиральної машини, пруткове полотно якого обладнане скребками і має знакозмінний напрямок транспортування для зменшення повздовжніх габаритів машини. Наведено аналітичні залежності впливу конструктивних і кінематичних параметрів транспортера-сепаратора на характер руху коренеплодів та проведений їх аналіз. В експериментальній частині представлено результати досліджень з визначенням домінуючих факторів на процес переведення коренеплодів на криволінійній ділянці між ланками транспортера-сепаратора. Здійснено порівняння теоретичних і експериментальних досліджень та запропоновано межі вибору раціональних конструктивно-кінематичних параметрів транспортера-сепаратора

Вплив потоку сипкого матеріалу на техніко-економічні показники роботи гвинтового конвеєра

The paper covers theoretical investigations of the movement of bulk material flow when it is fed by a pneumatic screw conveyor. Process calculation of the impact of bulk material particles during their transportation in guiding covers has been conducted. A mathematical model, which characterizes the overall energy spent on the impact of two particles, depending on impact velocity, physical and mechanical properties of bodies and impact conditions, has been developed. The limits of design and kinematic parameters that provide the effective application of pneumatic screw conveyors for transporting bulk materials have been defined

Anisotropic superconductivity and quantum oscillations in the layered dichalcogenide TaSnS2

TaSnS2 single crystal and polycrystalline samples are investigated in detail by magnetization, electrical resistivity, and specific heat as well as Raman spectroscopy and nuclear magnetic resonance (NMR). Studies are focused on the temperature and magnetic field dependence of the superconducting state. We determine the critical fields for both directions B∥c and B⊥c. Additionally, we investigate the dependence of the resistivity, the critical temperature, and the structure through Raman spectroscopy under high pressure up to 10 GPa. At a pressure of ≈3GPa the superconductivity is suppressed below our minimum temperature. The Sn NMR powder spectrum shows a single line which is expected for the TaSnS2 phase and confirms the high sample quality. Pronounced de Haas-van Alphen oscillations in the ac susceptibility of polycrystalline sample reveal two pairs of frequencies indicating coexisting small and large Fermi surfaces. The effective mass of the smaller Fermi surface is ≈0.5me. We compare these results with the band structures from DFT calculations. Our findings on TaSnS2 are discussed in terms of a quasi-two-dimensional BCS superconductivity

Incommensurate and multiple-q\boldsymbol{q} magnetic misfit order in the frustrated quantum spin ladder material antlerite, Cu3_3SO4_4(OH)4_4

In frustrated magnetic systems, the competition amongst interactions can introduce extremely high degeneracy and prevent the system from readily selecting a unique ground state. In such cases, the magnetic order is often exquisitely sensitive to the balance among the interactions, allowing tuning among novel magnetically ordered phases. In antlerite, Cu$_3$SO$_4$(OH)$_4$, Cu$^{2+}$ ($S=1/2$) quantum spins populate three-leg zigzag ladders in a highly frustrated quasi-one-dimensional structural motif. We demonstrate that at zero applied field, in addition to its recently reported low-temperature phase of coupled ferromagnetic and antiferromagnetic spin chains, this mineral hosts an incommensurate helical+cycloidal state, an idle-spin state, and a multiple-$q$ phase which is the magnetic analog of misfit crystal structures. The antiferromagnetic order on the central leg is reentrant. The high tunability of the magnetism in antlerite makes it a particularly promising platform for pursuing exotic magnetic order.Comment: 18.3 pages, 16 Figures, follow-up paper to arXiv:2203.1534

Coupled frustrated ferromagnetic and antiferromagnetic quantum spin chains in the quasi-one-dimensional mineral antlerite Cu3 SO4 (OH) 4

Magnetic frustration, the competition among exchange interactions, often leads to novel magnetic ground states with unique physical properties which can hinge on details of interactions that are otherwise difficult to observe. Such states are particularly interesting when it is possible to tune the balance among the interactions to access multiple types of magnetic order. We present antlerite Cu3SO4(OH)4 as a potential platform for tuning frustration. Contrary to previous reports, the low-temperature magnetic state of its three-leg zigzag ladders is a quasi-one-dimensional analog of the magnetic state recently proposed to exhibit spinon-magnon mixing in botallackite. Density functional theory calculations indicate that antlerite's magnetic ground state is exquisitely sensitive to fine details of the atomic positions, with each chain independently on the cusp of a phase transition, indicating an excellent potential for tunability.This project was funded by the German Research Foundation (DFG) via the projects A05, C01, C03, and C06 of the Collaborative Research Center SFB 1143 (project-id 247310070); GRK 1621 (project-id 129760637); the Würzburg-Dresden Cluster of Excellence on Complexity and Topology in Quantum Matter—ct.qmat (EXC 2147, project-id 390858490); through individual research grants, Grants No. IN 209/9-1 and No. PE 3318/2-1; and through project-id 422219907. D.K. and O.J. were supported by the Leibniz Association through the Leibniz Competition.Peer reviewe