Search results for "NICKEL"

Synthesis and characterization of NdNiO3 prepared by low temperature methods

1992

Abstract NdNiO3 has been prepared with an orthorhombic perovskite structure by a low temperature and low oxygen pressure method starting from a nickel(III) oxide precursor, β-NiO(OH). The compound LaNiO3 has also been obtained by this method. This chemical-precursor-based synthesis overcomes problems related to the use of high oxygen pressures in the synthesis.

Deposition of very thin uniform indium sulfide layers over metallic nano-rods by the Spray-Ion Layer Gas Reaction method

2013

Abstract Very thin and uniform layers of indium sulfide were deposited on nickel nano-rods using the sequential and cyclical Spray-ILGAR® (Ion Layer Gas Reaction) technique. Substrates were fabricated by electrodeposition of Ni within the pores of polycarbonate membranes and subsequent chemical dissolution of the template. With respect to the depositions on flat substrates, experimental conditions were modified and optimized for the present geometry. Our results show that nano-rods up to a length of 10 μm were covered uniformly along their full length and with an almost constant film growth rate, thus allowing a good control of the coating thickness; the effect of the deposition temperature…

A new approach for the synthesis of magnetic materials based on nitroxide free radicals and inorganic coordination polymers

2001

The use of nitronyl nitroxide (NN) radicals as spectators inside extended inorganic magnetic lattices is described. Two possibilities are presently being explored, namely, the design of oxalato-bridged bimetallic networks by using cationic NN radicals of the N-alkylpyridinium type as templating agents, and the design of bimetallic lattices based on hexacyanometalates and nickel(II) diaminocomplexes incorporating anionic NN radicals of the carboxyphenyl type.

From Bowls to Capsules: Assembly of Hexanuclear Ni II Rings Tailored by Alkali Cations

2020

An anionic hexanuclear NiII metallamacrocycle with endo and exo linking sites has been employed as a building block to generate a series of capsules and bowls of nanometric size. The supramolecular arrangement of the {Ni6 } rings was tailored by the size of the alkali cations, showing the transition from {Ni6 -M2 -Ni6 } capsules (M=LiI and NaI ) to {Ni6 -M} bowls (M=KI and CsI ). The alkyl co-cations are determinant to stabilize the assemblies by means of CH⋅⋅⋅π interactions on the exo side of the metallamacrocycles. The effect on the topology of the supramolecular assemblies of the cation size, cation charge, Et3 NH+ or Me4 N+ counter cations has been analyzed. Magnetic measurements reveal…

An approximate theoretical impedance analysis of the anodic dissolution of nickel across nickel(II) stabilised by means of competitive anions

2007

Abstract A theoretical impedance function for the anodic dissolution of nickel is developed by considering the hypothesis that there are two competitive anions which participate in the stabilization of the electrogenerated Ni(II) species. The experimental effect of chloride ion concentration on nickel electrodissolution process is analyzed by means of a mechanism that considers this competency. It is observed that an increased Cl − concentration causes an increase in Ni(I) surface concentration and a decrease in the kinetic constant rates of the considered mechanism. Moreover, an increased chloride concentration causes a flattening in the low frequencies inductive loop in the Nyquist plot r…

A novel ?-N-cyanate-bridged nickel dinier exhibiting ferromagnetic coupling: Di-?-cyanate-bis(aqua-2,2?:6?,2?-terpyridine)dinickel(II) hexafluorophos…

1986

Syntheses, crystal structures and magnetic properties of a series of μ-phenoxo-μ1,1-carboxylato-μ1,3-carboxylato trinickel(II) compounds.

2014

The work in this report describes the syntheses, characterization, crystal structures and magnetic properties of eight linear trinickel(ii) compounds of the composition [Ni(II)3(L(sal-pyr))2(propionate)4] (), [Ni(II)3(L(sal-pyr))2(benzoate)4]·CH3CN (), [Ni(II)3(L(sal-pip))2(acetate)4]·2CH3CN (), [Ni(II)3(L(sal-pip))2(propionate)4] (), [Ni(II)3(L(sal-pip))2(benzoate)4]·CH2Cl2 (), [Ni(II)3(L(sal-mor))2(propionate)4] (), [Ni(II)3(L(sal-mor))2(benzoate)4]·3CH2Cl2 () and [Ni(II)3(L(sal-mor))2(o-Cl-benzoate)4]·2CH3CN·2H2O (), where HL(sal-pyr), HL(sal-pip) and HL(sal-mor) are the 1 : 1 condensation products of salicylaldehyde and 1-(2-aminoethyl)-pyrrolidine, 1-(2-aminoethyl)-piperidine and 4-(2-…

Structural, spectral, and magnetic properties of end-to-end di-mu-thiocyanato-bridged polymeric complexes of Ni(II) and Co(II). X-ray crystal structu…

2002

Thiocyanatonickel(II) and thiocyanatocobalt(II) complexes of the composition Ni(NCS)(2)(HIm)(2) (1) and Co(NCS)(2)(HIm)(2) (2), where HIm = imidazole, were prepared and studied. In particular, the crystal structure of Ni(NCS)(2)(HIm)(2) was determined by X-ray methods. This compound crystallizes in the monoclinic system, space group P2(1)/n, with a = 7.720(1) A, b = 5.557(1) A, c = 13.774(3) A, beta = 102.54(3) degrees, and Z = 2. Its structure consists of a one-dimensional polymeric chain in which nickel(II) ions are bridged by two thiocyanate groups bonding in an end-to-end fashion in a trans arrangement. The Ni...Ni distance is 5.557(1) A. The crystal packing is determined by the intermo…

Defects and Reactivity at Oxide Surfaces: Experimental Aspects of the Interaction of Hydrogen, Co And Co2 with the Nio{001} Surface

1989

This paper summarizes some previous or more recent experimental results on chemical interaction, at moderate temperatures, of H, H2, CO and CO2 with the surfaces of nickel oxide, mainly the NiO {001} surface. These results are in a general agreement with theoretical predictions. Nearly perfect surfaces of maximal valency oxides cannot react with molecules. Dissociation of molecules is often required for chemisorption. Conversely, chemical reaction is usually observed either when molecules are predissociated or the surface has defects with an energy level high enough to enable both dissociation and chemisorption. On a nearly perfect, “in situ” cleaved, NiO {001} surface, partially atomized h…

UV-Photometrische Analyse kationisch erzeugter Polystyrole, 2. Quantitative Bestimmung von Endgruppen in Polystyrolen, dargestellt mit Acylperchlorat…

1984

Acyl perchlorates generated in styrene without a solvent by acyl chlorides and silver perchlorate gave polystyrenes with covalently bonded acyl groups. In order to gain secured values their number average relative molecular masses (Mn) were determined by different methods. The polystyrenes could be hydrogenated with hydrogen and Raney nickel at room temperature and under atmospheric pressure without attacking the phenolic nuclei. In addition IR data and a UV absorption at 294 nm of the polystyrenes revealed the presence of and olefinic bond, which was also found in a polystyrene obtained by polymerisation with perchloric acid. Also the quantitative evaluation of the hydrogeneation by UV abs…