The nucleation and growth of niobium pentaethoxide (NPE)-derived clusters in ethanol, through acid-catalyzed hydrolysis/condensation in the presence and absence of the silsesquioxane 1,2-bis(triethoxysilyl)ethane (BTESE), was monitored at 298-333 K by small-angle X-ray scattering. The data were analyzed with a newly derived model for polydisperse mass-fractal-like structures. At 298-313 K in th...

Niobium is one of the major alloying elements, among the refractory elements, contributing to the strengthening of superalloys. Consequently, data about its behavior and its migration mechanism in fcc-Ni are essential knowledge to understand and control the strengthening in such alloys. We present in this work Nb interactions, solubility and diffusion in Ni performed by using the GGA approximat...

We report experimental infrared spectra of neutral metal clusters in the gas phase. Multiple photon dissociation of the argon complexes of niobium clusters is used to obtain vibrational spectra in the 80-400 cm(-1) region. The observed spectra for Nb(9)Ar(n) (n=1-4) are different for different values of n. This is explained by the presence of two isomers of Nb(9) that have different affinities ...

The magnetic flux lattice undergoes a melting transition not only in high-T, oxide superconductors, but also in conventional superconductors, as recently observed in superconducting niobium films. Small-angle neutron scattering was used to investigate the properties of the magnetic flux lattice in a large, high-quality single crystal of niobium. The small London penetration depth of niobium giv...

The salting-out effect of various solutions of electrolyte in the extraction of tantalum and niobium using aqueous biphasic system (ABS) was investigated. This was achieved by leaching ball-milled Tantalite ore with mineral acids (H2SO4 and HF) in the ratio of 3:1. The leached liquor was then divided into five parts and each part mixed with ABS formed (e.g. PEG-3350/20wt/wt Na2CO3) for the extr...

Novel mixed amido/imido/guanidinato complexes of niobium are reported. The complexes were synthesized by insertion of two equivalents of di-isopropylcarbodiimide (i-Pr-cdi) or bis-cyclohexylcarbodiimide (Cy-cdi) respectively, into the niobium-amido bonds of [Nb(NR(2))(3)(N-t-Bu)] (, R = Me; , R = Et) starting out from [NbCl(3)(N-t-Bu)(py)(2)] and the respective LiNR(2) reagent (py = pyridine). ...

Far-infrared absorption spectra of small neutral and cationic niobium clusters containing five to nine Nb atoms have been obtained by multiple photon dissociation spectroscopy of their argon complexes. The experimental far-IR spectra are recorded in the 85-600 cm(-1) region and cover the range of the structure-specific vibrational fundamentals, i.e., the finger-print range, for these metal clus...

Niobium coatings deposited by magnetron sputtering were evaluated as a possible surface modification for stainless steel (SS) substrates in biomedical implants. The Nb coatings were deposited on 15 mm diameter stainless steel substrates having an average surface roughness of 2 μm. To evaluate the biocompatibility of the coatings three different in vitro tests, using human alveolar bone derived ...

The title compound, bis(ethylenediaminium) mu-oxo-bis[tetrafluorooxoniobium(V)], (C2H10N2)2[Nb2O3F8], is a novel organically templated niobium oxyfluoride. It consists of isolated [Nb2O3F8]4- octahedral dimers charge balanced by ethylenediaminium cations, two of which lie about inversion centres. Two NbO2F4 octahedra are fused through a common O atom to form the dimers. Characteristic short ter...