[en] The uranium nickel phosphide U₆Ni₁₅P₁₀ was prepared for the first time and its crystal structure has been determined from single-crystal X-ray diffraction data. The compound crystallises with hexagonal unit cell of the Ce₆Ni₁₅P₁₀ type: space group P6₃/m, Z=2, a=1641.04(8) pm, c=380.90(6) pm. The refined crystal structure reveals characteristic features of transition metal phosphides with metal-to-nonmetal ratio close to 2

[en] We present the results of exploratory measurements of the electrical resistivity ρ(T), magnetoresistivity MR, magnetic susceptibility χ(T), and specific heat C(T) on polycrystalline Ce₃Pd₅Si. The temperature variation of ρ(T) and of χ(T) from room temperature down to ∼10 K indicate largely normal-metal behaviour. Below 10 K ρ(T) decreases rapidly with lowering temperature and displays a knee at 3.5 K. χ(T) remains Curie-Weiss-like down to 100 K, with the paramagnetic Curie temperature of +12.7 K, and the effective magnetic moment of 2.37 μ_B/mol_Ce. At lower temperatures the inverse susceptibility χ^-1(T) reveals crystal field effects but no anomaly hinting that magnetic phase transition is seen down to 1.7 K. The MR is large and negative below 30 K. In C(T) there is an upturn towards very large values at low temperatures, and an anomaly is seen at 3.5 K, typical of magnetic ordering

[en] The wear behaviour of an austenitic stainless steel is analysed using a tribometer working in pressurised high temperature water (PHTW). The precise contact conditions, low pressure impact and sliding contacts, play an important role on the surface wear in this corrosive medium. The tests which include both impact and sliding are the most severe. The friction films formed during these tests are compared with those obtained with pure oxidation. It is shown that these films participate in the formation of elongated 'indents' observed on the surfaces. Nano-indentation measurements consolidate this hypothesis. (authors)

[en] The crystal structure of U₂Cu₂As₃O was determined from single-crystal X-ray data and refined to a residual of R = 0.037, R_w = 0.034, for 443 reflections with I > σ(I) and 22 variables. It is of a new type with tetragonal space group P4/nmm, Z = 2, and lattice parameters a = 3.9111(2) Angstrom and c = 17.916(4) Angstrom. A close relationship between the crystal structures of U₂Cu₂As₃O and UCuAs₂ is discussed. U₂Cu₂As₃O appears to be the first known oxypnictide among uranium compounds. However, in view of the results obtained for U₂Cu₂As₃O, another uranium compound, previously denoted as open-quotes U₄Cu₄P₇,close quotes is believed now to be U₂Cu₂P₃O, closely related to the arsenide

[en] In order to extend our knowledge on effects of substitution of gallium by transition metal in solid solutions of gallides with the tetragonal BaAl_4-type crystal structure we studied physical properties of polycrystalline samples of CePd_xGa_4_−_x (x = 0.2−0.8). X-ray diffraction confirmed that the unit-cell volume of the system changes in a non-monotonic way with a maximum around x"∗ = 0.6. We performed magnetization, specific heat, electrical resistivity and thermoelectric power measurements in wide temperature and magnetic field ranges. Magnetic moments of Ce"3"+ ions are very close to the value corresponding to the localized 4f-state in the whole x-range covered, yet their variation with x coincides with that of lattice parameters, with a minimum close to x"∗. The alloys order ferromagnetically at low temperatures, which causes distinct anomalies of the measured properties. The ordering temperature decreases with increasing the Pd content from 3.7 K for x = 0.2 down to 1.3 K for x = 0.8. The results suggest that no quantum critical transition can be approached within the solid solution existence range. - Highlights: • CePd_xGa_4_−_x is a solid solution with pelectron atoms (Ga) swapped for d-electron ones (Pd). • Swapping modifies in the strength of f−(p,d)hybridization. • Magnetic, thermodynamic and electron transport properties are determined at low temperatures. • CePd_xGa_4_−_x adopt magnetic order in whole range of existence of the solution. • No quantum critical transition can be approached within the solid solution existence range

[en] A new series of ternary uranium intermetallics U₂TSi₃ (T ≡ Fe, Co, Ni or Cu) has been discovered. All these phases crystallize in the hexagonal A1B₂-type structure, except for U₂CuSi₃ which is of the tetragonal α-ThSi₂ type. The magnetic properties of the new compounds were investigated by means of DC magnetization and AC susceptibility measurements. The results show all the main characteristics of a re-entrant spin-glass behaviour at low temperatures in all the ternaries studied. Owing to some structural properties of these compounds they could be classified as non-magnetic atom disorder spin glasses. (author)

[en] The crystal structure of a new intermetallic compound Ce₆Pt₁₁In₁₄ has been determined from single crystal X-ray data and was refined by a full-matrix least-squares method down to R₁=0.0497 for 1215 structure factors and 96 parameters. The unit cell is monoclinic, space group C2/m, Z=2 with the lattice parameters: a=22.729(5) A, b=4.3960(10) A, c=14.780(3) A and β=118.35(3) deg. . It represents a new type of crystal structure of intermetallic compounds

[en] Magnetic behaviour of meso-tetratotylporphyrins and meso-(4N-methyltetrapirydyl)porphyrin iodide, as well as their iron and cobalt complexes are reported

[en] Neutron powder diffraction and magnetic measurements have been carried out on RCu_xGe₂ (R=Ho, Er) compounds. Both compounds crystallize in the orthorhombic CeNiSi₂-type structure (space group Cmcm) and they are antiferromagnets with the Neel temperature equal to 4.5 K for R=Er and 8.0 K for R=Ho. Neutron diffraction measurements indicate the presence of collinear magnetic structures of the G_z mode in HoCu_0.33Ge₂ and G_x mode in ErCu_0.25Ge₂

[en] A new cerium compound Ce₂Co₆Al₁₉ was prepared in polycrystalline form and studied by means of X-ray diffraction, magnetic susceptibility, electrical resistivity and specific heat measurements. The results obtained indicate that the new phase exhibits distinct non-Fermi liquid features in its low-temperature thermal properties, at least over a decade in temperature. Yet, at the lowest temperatures reached a cross-over into Fermi liquid behavior is observed, as can be expected for a system located in the vicinity of a magnetic quantum critical point