A series of pseudosymmetrical structures of formula K10(M2OnF11-n)3X (M = V and Nb, n = 2, X = (F2Cl)1/3, Br, Br4/2,I4/2; M = Mo, n = 4, X = Cl, Br4/2, I4/2) illustrates generation of polar structures with the use of Λ-shaped basic building units (BBUs). For a compound to belong to a polar space group, dipole moments of individual species must be partially aligned. Incorporation of d(0) early t...

In this paper the feasibility of NbAl3/Al2O3 nanocomposite formation through mechanochemical reaction between Al and Nb2O5 and the effect of mechanical activation on the kinetic and reaction mechanism were investigated. Structural and phase evolution during mechanical alloying were studied by employing transmission electron microscopy (TEM)...

The use of liquid-liquid extraction for the separation of tantalum from niobium was demonstrated. Tantalum and niobium spectrographically free of each other were prepared in quantity on a continuous basis.

We report on a 850 GHz SIS heterodyne receiver employing a RF tuned niobium tunnel junction with a current density of 14kA/cm2, fabricated on a 1 μm Si3N4 supporting membrane. Since the mixer is designed to be operated well above the superconducting gap frequency of niobium (2 /h ≈ 690 GHz), special care has been taken to minimize niobium transmission line losses. Both Fourier Transform Spectro...

This study aims to investigate the effects on hot cracking susceptibility of fluoride powders such as CaF2, NaF, LiF, and metal Mn, Ti, Nb mixed Ti-Nb deposited 316L stainless steel during TIG (Tungsten Inert Gas) welding process. A self-restraint bench test using specimens trapezoidal shape 3 mm thickness was selected. The obtained results weldability with different were compared those convent...

Metallic niobium powder was produced for applications in electric capacitors via calciothermic reduction of niobium hydroxide in molten CaCl2. Sub-micrometer spherical metallic particles with coral-like morphologies reflected the particle size of the starting oxide powder. A fine powder was obtained from the mixtures of niobium hydroxide and CaO or Ca(OH)2, respectively. Sintered pellets of the...

A method for bonding a niobium wire to a niobium thin film i s described The bonds are to be used as superconducting connections between wire-wound gradiometers and thin-film coupling coils on oc SOUIOS. The method is characterized by two steps. Firstly. the hardness of the niobium wire is reduced by a heat treatment. Secondly, the niobium film is covered with a thin layer of palladium to preve...

Recent results at 1 THz using normal-metal tuning circuits have shown that SIS mixers can work well up to twice the gap frequency of the junction material (niobium). However, the performance at 1 THz is limited by the substantial loss in the normal metal films. For better performance superconducting films with a higher gap frequency than niobium and with low RF loss are needed. Niobium nitride ...

The growth of niobium carbide in austenite involves the diffusion of both niobium and carbon. These elements diffuse at very different rates. A model is presented for the overall transformation kinetics of niobium carbide precipitation in austenite that takes into account the multicomponent nature of the diffusion process while at the same time allows for the curvature of the transformation fro...