Reaction Of Nd Research Articles

Parameters Affecting Pressureless Sintering of α'-Sialons with Lanthanide Modifying Cations

ABSTRACTμ-silicon nitride forms a range of solid solution Mx(Si,Al)12(0,N)16 where x = 2 and M is Li+, Ca2+, y3+ or certain lanthanide cations. This paper reports the formation of Ln-α'-sialons by the reaction of Si3N4 with AIN and Ln2O3 where Ln=Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y. Transformation reactions of Nd, Sm, Gd, Ho, Er and Y cations occurring during liquid phase pressureless sintering are reported. The effects of the volume and viscosity of the liquid phase and the amountof secondary N-melilite on sintering are discussed.

ChemInform Abstract: Preparation and Crystal Structure of Nd2SeSiO4.

AbstractViolet rod‐like single crystals of the title selenosilicate, obtained by reaction of Nd, Se, and I2 (1:1:2.5) and subsequent reaction with quartz glass powder at 850 °C, belong to the orthorhombic space group Pbcm with Z=4.

ChemInform Abstract: The Radical Formation of Diphthalocyanine Complexes of Lanthanum(III), Neodymium(III) and Yttrium(III) with p‐Benzoquinone.

AbstractThree species (I)‐(III) including the radical (II) of neodymium(III) phthalocyanine were obtained from a crude Nd(III) phthalocyanine mixture (prepared by reaction of Nd(III) acetate and ophthalonitrile) by column chromatography on silica gel.

The infrared multiphoton excitation and photochemistry of DN3

Multiphoton excitation and dissociation of DN3 by short CO2 laser pulses is shown to be a collisionless process. The characteristic features of this multiphoton process are systematically studied. The average number of photons absorbed per DN3 molecule and the absolute dissociation yield show a strong dependence on the peak laser intensity. Resonantly enhanced coherent multiphoton excitation, rather than stepwise incoherent excitation, is suggested. The primary dissociation products of DN3 are ND[1Δ] and N2. Formation of vibrationally excited ND[1Δ] intermediates is suggested. The reactions of ND[1Δ] with DN3 lead to chemiluminescent signals originating from the formation of electronically excited ND2[2A1] and ND[3Π]. Formation of the ND[3Π] intermediate is attributed to a reaction of ND[1Δ] and vibrationally excited DN*3 molecules: ND[1Δ]+DN*3→ND[3Π]+ND[3Σ−]+N2.

Activation Cross Sections for (n, p) and (n, α) Reactions on Nd, Sm, Yb and Lu at 14.6 MeV

Activation cross sections for the (n, p) and (n, α) reactions of Nd, Sm, Yb and Lu have been measured at 14.6 MeV by using a Ge(Li) γ-ray detector. The following cross sections (in millibarns) have been obtained: 150Sm(n, p) 150Pm, 7.19±1.01; 173Yb(n, p) 173Tm, 13.5±2.8; 175Lu(n, p) 175Yb, 18.5±2.2;146Nd(n,α) 143Ce, 4.42±0.47; 152Sm(n, α) 149Nd, 2.81±0.42; 174Yb(n, α)171Er, 1.22±0.23 and 176Lu(n, α)173Tm, 2.30±0.57. The results are compared with predictions based on the evaporation, the pre-equilibrium and other models. The present experimental (n, p) cross sections agree fairly well with the pre-equilibrium model predictions. A comparison made between the experimental (n, α) cross sections and the predictions of the pre-equilibrium model suggests the existence of a mechanism of pre-equilibrium emission in the (n, α) reaction in this mass region.

Quantitative aspects of the reaction of ND 3 with positive ions and the neutralization of ammonium ions in irradiated cyclohexane solutions

The formation of HD in the reaction of ND 3 with positive solvent ions in γ-irradiated cyclohexane solutions has been investigated as a function of solute concentration. From the observed concentration dependence the competition between geminate recombination and the scavenging reaction for the positive ions of cyclohexane is described by the reactivity parameter α ND 3 = 0·85 mol −1. The yield of HD is decreased upon addition of C 2H 4 to the ND 3-cyclohexane solution. This has been found to be due to the fact that ethylene competes with ammonia for the positive ions and also scavenges hydrogen atoms. A quantitative treatment of these data shows that most of the HD ( ca. 75 per cent) is formed via thermal hydrogen atoms produced upon neutralization of ammonium ions with electrons. G(HD) also is decreased in solutions containing electron scavengers in addition to the ND 3. It is concluded that the reaction of ammonium ions with secondary negative ions does not yield free hydrogen atoms. Quantitative aspects on the basis of ion pair lifetimes are discussed.

Physicochemical investigation of the reaction between neodymium hydroxide and hydrogen peroxide

1. An investigation of the reaction of Nd(OH)3 with H2O2 within wide concentration limits made it possible to distinguish two phases of the peroxide type: Nd2O5 · 2H2O and Nd2O4 · 2H2O. 2. Anhydrous neodymium peroxide compounds were not obtained when the “residues” Nd2O5 · 2H2O and Nd2O4 · 2H2O were separated and subsequently dehydrated. 3. The probable formulas of the peroxide-type solid phases which were distinguished are characterized by the presence of perhydroxyl and hydroxyl groups, and by oxygen bonds between neodymium atoms.