Metal site doping in the narrow-gap semiconductor FeGa₃

The effects and feasibility of metal site doping of the tetragonal diamagnetic insulator FeGa₃ by Fe/Co, Fe/Mn and Co/Ni substitution were investigated by X-ray, electron probe microanalysis, electrical resistivity, specific heat and magnetic susceptibility measurements. Substitution of Fe by Co in FeGa₃ does not change its structure type and preserves the structure of the binary parent compound (FeGa₃), whereas the solubility of Mn in the FeGa₃ structure type is limited to 3 at.% and a finite solubility of Ni in CoGa₃ is not detected.Методами рентгенівського, мікрорентгеноспектрального аналізу, дослідження електроопору, питомої теплоємності і магнетної сприйнятливості вивчено можливість та вплив легування Fe/Co, Fe/Mn і Co/Ni у положеннях атомів металу в тетрагональній структурі діамагнетного ізолятора FeGa₃. Заміщення атомів Fe на Co у сполуці FeGa₃ не змінює її кристалічну структуру. Розчинність Mn у FeGa₃ не перевищує 3 at.%, а розчинність Ni у CoGa₃ не виявлено.Методами рентгеновского, микрорентгеноспектрального анализа, исследования электросопротивления, удельной теплоемкости и магнитной восприимчивости исследована возможность и влияние легирования Fe/Co, Fe/Mn и Co/Ni в положениях атомов металла в тетрагональной структуре диамагнитного изолятора FeGa₃. Замещение атомов Fe на Co в соединении FeGa₃ не изменяет ее кристаллическую структуру. Растворимость Mn в FeGa₃ не превышает 3 at.%, а растворимость Ni в CoGa₃ не выявлено

Effect of Rare Earth Ions on the Properties of Composites Composed of Ethylene Vinyl Acetate Copolymer and Layered Double Hydroxides

BACKGROUND: The study on the rare earth (RE)-doped layered double hydroxides (LDHs) has received considerable attention due to their potential applications in catalysts. However, the use of RE-doped LDHs as polymer halogen-free flame retardants was seldom investigated. Furthermore, the effect of rare earth elements on the hydrophobicity of LDHs materials and the compatibility of LDHs/polymer composite has seldom been reported. METHODOLOGY/PRINCIPAL FINDINGS: The stearate sodium surface modified Ni-containing LDHs and RE-doped Ni-containing LDHs were rapidly synthesized by a coprecipitation method coupled with the microwave hydrothermal treatment. The influences of trace amounts of rare earth ions La, Ce and Nd on the amount of water molecules, the crystallinity, the morphology, the hydrophobicity of modified Ni-containing LDHs and the adsorption of modifier in the surface of LDHs were investigated by TGA, XRD, TEM, contact angle and IR, respectively. Moreover, the effects of the rare earth ions on the interfacial compatibility, the flame retardancy and the mechanical properties of ethylene vinyl acetate copolymer (EVA)/LDHs composites were also explored in detail. CONCLUSIONS/SIGNIFICANCE: S-Ni₀.₁MgAl-La displayed more uniform dispersion and better interfacial compatibility in EVA matrix compared with other LDHs. Furthermore, the S-Ni₀.₁MgAl-La/EVA composite showed the best fire retardancy and mechanical properties in all composites

A Lanthanum‐Filled Carbon–Boron Clathrate

We report a carbon-boron clathrate with composition 2 La@B6C6 (LaB3C3). Like recently reported SrB3C3,[1] single-crystal X-ray diffraction and computational modelling indicate that the isostructural La member crystallizes in the cubic bipartite sodalite structure (Type-VII clathrate) with La atoms encapsulated within truncated octahedral cages composed of alternating carbon and boron atoms. The covalent nature of the B−C bonding results in a hard, incompressible framework, and owing to the balanced electron count, La3+[B3C3]3− exhibits markedly improved pressure stability and is a semiconductor with an indirect band gap predicted near 1.3 eV. A variety of different guest atoms may potentially be substituted within Type-VII clathrate cages, presenting opportunities for a large family of boron-stabilized, carbon-based clathrates with ranging physical properties

Crystal structure of lanthanum borocarbide, La10B9C12

B9C12La10, tetragonal, P4(1)2(1)2 (no. 92), a = 8.6447(4) Angstrom, c = 25.787(2) Angstrom, V = 1927.1 Angstrom(3), Z = 4, R-gt(F) = 0.043, wR(ref)(F) = 0.065, T = 293 K