The magnetocaloric properties of the ferromagnetic compounds GdScSi (TC = 354(2) K) and GdScGe (TC = 349(2) K) (tetragonal CeScSi-type structure refined from single crystal diffractometer data, space ...group I4/mmm) have been determined. The field dependence of the magnetic entropy ΔSm change and of the refrigerant capacity RC have been obtained from magnetization measurements. At the TC Curie temperature, ΔSm for GdScSi and GdScGe is respectively equal to 2.5 and 3.3 J/kgGd K for a magnetic field change of 2 T; the values are comparable to those determined previously for Gd7Pd3 and Gd4Bi3 which exhibit also a TC-temperature higher than room temperature. Both microstructural and the analysis of the magnetocaloric response are used to assess the single phase nature of the samples.
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► Crystal structure of GdScSi and GdScGe data. ► GdScSi and GdScGe exhibit ferromagnetism below 354 and 349 K ► Magnetocaloric properties of GdScSi and GdScGe.
The electronic structure of the ternary nitride Li2ZrN2 is examined from ab initio with DFT computations for an assessment of the properties of chemical bonding. The compound is found insulating with ...1.8eV band gap; it becomes metallic and less ionic upon removal of one equivalent of Li. The chemical interaction is found mainly between Zr and N on one hand and Li and N on the other hand. While all pair interactions are bonding, antibonding N–N interactions are found dominant at the top of the valence band of Li2ZrN2 and they become less intense upon removal of Li. From energy differences the partial delithiation leading to Li2−xZrN2 (x=∼1) is favored.
Trigonal structure of Li2ZrN2 showing the Zr–N–Li layers along the c-axis. Display omitted
► Li2ZrN2 calculated insulating with a 1.8eV gap in agreement with its light green color. ► Lithium de-intercalation is energetically favored for one out of two Li equivalents. ► Li plays little role in the change of the structure, ensured by Zr and N binding. ► Similar changes in the electronic structure as for various intercalated phases of ZrN.
CuSbS2 was tested as a negative electrode material for sodium-ion batteries. The material synthesized by ball milling offers a specific charge of 730 mAh g−1, close to the theoretical value ...(751 mAh g−1), over a few cycles. The reaction mechanism was investigated by means of operando X-ray diffraction, 121Sb Mössbauer spectroscopy, and Cu K-edge X-ray absorption spectroscopy. These studies reveal a sodiation mechanism that involves an original conversion reaction in two steps, through the formation of a ternary phase, CuSb(1−x)S(2−y), as well as a NaxS alloy and Sb, followed by an alloying reaction involving the previously formed Sb. The desodiation process ends with the reformation of the ternary phase, CuSb(1−x′)S(2−y′), deficient in Sb and S; this phase is responsible for the good reversibility observed upon cycling.
•A ternary phase CuSbS2 is tested as anode material for sodium ion batteries.•Reversible specific charge of 730 mAh g−1 for few cycles without optimization.•Combination of conversion and alloying reactions mechanism.
Synthetic investigation of ternary systems of lanthanide ions, chrysin, and phenanthroline in mixed aqueous-methanolic solutions led to hybrid crystalline materials. Physicochemical characterization ...in the solid-state and solution reveals structural-electronic features, which upon theoretical calculations formulate a global structural speciation profile projecting correlations with luminescence and magnetism, collectively supporting materials applications.
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The diversity of metallodrugs used as diagnostics and therapeutics in disease treatment and their prevailing side-effects in human metabolism present an urgent need for exploration and development of new metal-based agents. Among them, rare earth metals constitute a unique case when combining with natural binders, such as antioxidant flavonoids. To that end, a multiparametric synthetic investigation of ternary systems of Er(III), Dy(III), Sm(III) with flavone chrysin and N,N’-aromatic chelator (phen) led to crystalline mononuclear materials, which were physicochemically characterized through elemental analysis, FT-IR, UV–Visible, ESI-MS, and X-ray crystallography. The coordination environment of trivalent lanthanides in each assembly reveals the salient features of ternary component binding modes, with the contribution of chrysin to lanthanide coordination validated though BVS and Hirshfeld surface analysis. The structural, electronic, and magnetics data of the new species signify the importance of structural speciation in drawing correlations with optical and magnetic properties, thus formulating well-defined physicochemical profiles and projecting essential attributes linked to the development of new materials of potential diagnostic-therapeutic value.
Bulk and local properties of DyRhSn Łątka, K.; Gurgul, J.; Pacyna, A.W. ...
Journal of alloys and compounds,
07/2009, Letnik:
480, Številka:
1
Journal Article, Conference Proceeding
Recenzirano
Electric, magnetic and
119Sn Mössbauer spectroscopy measurements were carried out on the hexagonal DyRhSn, where all atoms occupy single crystallographic sites. This stannide undergoes a transition ...from a paramagnetic to an antiferromagnetic state at
T
N
=
7.5(1)
K. The obtained results are compared with previously published magnetic and neutron diffraction data.
Systematic synthetic reactivity in binary-ternary Ni(II):iminodipropanol:N,N’-aromatic chelator systems unravels an interwoven network of hybrid mononuclear Ni(II) complexes with variable ...coordination sphere composition. Structural variant and interconversion transformations exemplify distinct physicochemical properties, revealing diverse lattice architecture-spectroscopic correlations with theoretical electronic modeling and formulating nickel chemical reactivity profiles-patterns useful in materials development.
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The importance of structural speciation in the control of chemical reactivity in Ni(II) binary-ternary systems, involving (O,O,N)-containing substrates (1,1′-iminodi-2-propanol), and aromatic chelators (2,2′-bipyridine, 1,10-phenanthroline), prompted the systematic synthesis of new crystalline materials characterized by elemental analysis, FT-IR, UV-Visible, Luminescence, magnetic susceptibility, and X-ray crystallography. The structures contain mononuclear octahedral assemblies, the lattice architecture of which exemplifies reaction conditions under which conformational variants and solvent-associated lattice-imposed complexes are assembled. Transformations between complex species denote their association with reactivity pathways, suggesting alternate synthetic methodologies for their isolation. Theoretical work (Hirshfeld, Electrostatic Potential, DFT) signifies the impact of crystal structure on energy profiles of the generated species. The arisen physicochemical profiles of all compounds portray a well-configured interwoven network of pathways, projecting strong connection between structural speciation and Ni(II) reactivity patterns in organic-solvent media. The collective results provide well-defined parameterized profiles, poised to influence the synthesis of new Ni(II)-iminodialcohol materials with specified structural-magneto-optical properties.
We present measurements of cross sections for production of a leptonically decaying Z boson in association with a large-radius jet in 13 TeV proton-proton collisions at the LHC, using 36 fb - 1 of ...data from the ATLAS detector. Integrated and differential cross sections are measured at particle level in both a flavor inclusive and a doubly b -tagged fiducial phase space. The large-radius jet mass and transverse momentum, its kinematic relationship to the Z boson, and the angular separation of b -tagged small-radius track jets within the large-radius jet are measured. This measurement constitutes an important test of perturbative quantum chromodynamics in kinematic and flavor configurations relevant to several Higgs boson and beyond-Standard-Model physics analyses. The results highlight issues with modeling of additional hadronic activity in the flavor-inclusive selection, and a distinction between flavor-number schemes in the b -tagged phase space.
Phase analytical studies in the rare earth metal-zinc-germanium systems led to the synthesis of eight new ternary germanides. The compounds RE sub(4)Zn sub(5)Ge sub(6) (RE=Y, Dy, Ho, Er) crystallize ...with the ortho-rhombic Gd sub(4)Zn sub(5)Ge sub(6) type structure, space group Cmc2 sub(1). Er sub(5)Zn sub(4-x)Ge sub(6) and the low-temperature modification of Tm sub(5)Zn sub(4-x)Ge super(6) adopt the Eu sub(5)Cd sub(4-x)Bi sub(6) structure, while HT-Tm sub(5)Zr sub(4-x)Ge sub(6) and LU sub(5)Zn sub(4-x)Ge sub(6) crystallize with a new type. All eight structures were refined on the basis of single crystal diffractometer data. The common structural motif is the distorted tetrahedral germanium coordination of the zinc atoms. The ZnGe sub(4) tetrahedra are condensed via common edges and/or corners, leading to a two-dimensional polyanionic network in LT-Tm sub(5)Zn sub(4-x)Ge sub(6) and three-dimensional ones in HT-Tm sub(5)Zn sub(4-x)Ge sub(6) and Y sub(4)Zn sub(5)Ge sub(6). In all three structure types part of the germanium atoms form dumb-bells with single bond character. The RE sub(4)Zn sub(5)Ge sub(6) germanides are electron-precise Zintl phases with an electron partitioning (4RE super(3+))(5Zn super(2+))(Ge super(6) sub(2) super(-)) (4Ge super(4-)). This is different in the RE sub(5)Zn sub(4-x)Ge sub(6) phases. Both structure types of that composition show systematic defects on one zinc site. These zinc defects compensate the excess electron that would remain according to an electron partitioning (5RE super(3+)) (4Zn super(2+)) (Ge2 super(6) sub(2) super(-)) (4Ge super(4-)) times e super(-). These crystal chemical features are supported by electronic structure calculations that reveal optimization of Zn-Ge and Ge-Ge bonding through lowering the Fermi energy.
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