Systematic investigation of the formation of 1D alpha-Si(3)N(4) nanostructures by using a thermal-decomposition/nitridation process

This article describes a simple thermal-decomposition/nitridation method for the large-scale synthesis of 1D alpha-Si(3)N(4) nanostructures, such as millimeter-scale microribbons, nanosaws, nanoribbons, and nanowires. These nanostructures are systematically investigated by checking the product deposited at different areas by using powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and electron energy loss spectroscopy. Studies show that all these nanostructures have a single-crystalline nature and predominantely grow along the [011] direction. These 1D nanostructures are formed by thermal decomposition, followed by the nitridation of SiO.     

The influence of nitrogen vacancies on the magnetic behaviour of rare-earth nitrides

The rare-earth nitrides are ferromagnetic semiconductors with promise for spintronic devices. Their most common dopants are nitrogen vacancies (V_N), with a small enough energy of formation that they exist at of order 1% in epitaxial films. Here we report preliminary investigations of their effect on the magnetic states of two of them in the series, GdN and EuN. In the former we find an enhanced Curie temperature at very high V_N concentration, and the Eu²⁺ ions associated with V_N in the latter show strong exchange with their Eu³⁺ neighbours that might form the basis of a diluted magnetic semiconductor.     

Nickel Molybdenum Bimetallic Nitrides as Efficient Catalysts for the Hydrodeoxygenation of Methyl Palmitate

Highly efficient catalysts play an important role in the effective use of biomass oil to produce clean fuel. In this work, pure-phase Ni−Mo bimetallic nitrides (Ni₂Mo₃N and Ni₃Mo₃N) with different stoichiometric ratios are prepared by temperature-programmed nitridation of the metal oxide precursors in ammonia, which are investigated in the hydrodeoxygenation of methyl palmitate in the fixed-bed reactor at moderate conditions. The physical and chemical properties of catalysts were evaluated by H₂-TPR, XRD, SEM, TEM, XPS, and CO chemisorption. The Ni₂Mo₃N catalyst presents the best methyl palmitate hydrogenation activity (con.%=95.4 %) and the maximum hexadecane selectivity (95.0 %), which is obviously higher than those of Ni₃Mo₃N and Mo₂N catalysts. By introducing transition metal Ni into the Mo₂N lattice to form nickel-molybdenum bimetallic nitride, the lattice structure and electronic structure of the Mo active center have been changed, which greatly enhances the hydrodeoxygenation performances for the transformation of biomass oil to clean fuel.