Study on dissolution mechanism of mineral/liquid
The niobium-tantalum bearing mineral used in this paper was natural niobium-tantalum mineral from Yichun, Jiangxi, China. ... Mn, Nb, Ta during the dissolution of metal elements on the surface of niobium-tantalum bearing mineral. Fig. 11 shows the driving mechanism diagram of the process of hydrofluoric acid leaching of (Fe,Mn) ...
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New material platform for superconducting transmon qubits …
Here, we fabricate two-dimensional transmon qubits that have both lifetimes and coherence times with dynamical decoupling exceeding 0.3 milliseconds by replacing niobium with tantalum in the...
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Tantalum / Niobium / Polymer | AVX
Failure Mode Comparison of Tantalum and Niobium Oxide Capacitors Written By: George Zhang Abstract: The automotive industry has become highly dependent on advanced sensing and computing. ... Figure 2: The dielectric surface area of a tantalum capacitor anode compared to its finished size. Over the course of the following decades, tantalum ...
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Niobium and tantalum
Niobium and tantalum are transition metals that are almost always found together in nature because they have very similar physical and chemical properties. Their properties of hardness, conductivity, and resistance to corrosion largely determine their primary uses today. The leading use of niobium (about 75 percent) is in the production of high …
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Niobium
Niobium. Columbium-tantalum ore, or coltan, is an important component of modern electronics (e.g., smart phones) and forms a major source of conflict in eastern DRC and Rwanda, which are currently the world's largest exporters. ... Surface dissolution of minerals is carried out by HCl at pH = 2 through 10 min. The results showed that the ...
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Effect of Adsorbed Water Molecules on the Surface Acidity of Niobium …
DOI: 10.1021/ACS.JPCC.1C02230 Corpus ID: 234837323; Effect of Adsorbed Water Molecules on the Surface Acidity of Niobium and Tantalum Oxides Studied by MAS NMR @article{Chen2021EffectOA, title={Effect of Adsorbed Water Molecules on the Surface Acidity of Niobium and Tantalum Oxides Studied by MAS …
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Superconductivity of Tantalum, Niobium and Lanthanum …
The derivatives of a tantalum‐silver junction made by a sputtering method clearly show much poorer gap and phonon induced characteristics than a junction made on an outgassed surface. Analysis of the latter gives α2(ω)F(ω) with phonon peaks at energies in agreement with neutron scattering, μ* = 0.11 and λ = 0.69 in good agreement with ...
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Understanding the Tantalizing Benefits of Tantalum for …
Contact: Peter Genzer, (631) 344-3174 | Written by Denise Yazak. share: Understanding the Tantalizing Benefits of Tantalum for Improved Quantum …
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Niobium | Properties, Uses, & History of the Chemical Element
Niobium is roughly 10 times more abundant in the crust of the Earth than is tantalum. Niobium, more plentiful than lead and less abundant than copper in the Earth's crust, occurs dispersed except for relatively few minerals. Of these minerals, the columbite–tantalite series, in which columbite (FeNb 2 O 6) and tantalite (FeTa 2 O 6) …
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Study of Bone Regeneration and Osteointegration Effect of a
Titanium-tantalum-niobium-zirconium (Ti-Ta-Nb-Zr) alloy is a novel material currently available for orthopedic applications. However, these scaffolds, manufactured using traditional methods, present disadvantages such as irregular pore size, unsuitable mechanical features, and poor connectivity betw …
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Effect of Adsorbed Water Molecules on the Surface Acidity of Niobium …
Niobium oxides and tantalum oxides are typical solid acid catalysts that exhibit high activity and high water-resistance in the aqueous environment.
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Influence of niobium/tantalum doping on the hydrogen …
The adsorption energy of H 2 or H on the ZrCo (110) surfaces can be obtained by follow: (2) E ads = E slab + H x − E slab − 1 ( 3 − x) E H 2 where E slab + H x, E slad, and E H 2 are the energies of the adsorption system, the pure surface, and the adsorbed species, respectively. H x means one of H 2 or H.
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Improving the work function of the niobium surface of SRF …
An in situ plasma processing for SNS SRF cavities has been developed to remove hydrocarbons from cavity surface.. Reactive oxygen plasma is very effective to remove hydrocarbons from niobium top surface.. Reactive oxygen plasma processing increases the work function of niobium surface in the range of 0.5–1.0 eV.. It was …
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Niobium and Tantalum Statistics and Information
Niobium and columbium are synonymous names for the chemical element with atomic number 41; columbium was the name given in 1801, and niobium (Nb) was the name officially designated by the International Union of Pure and Applied Chemistry in 1950. Niobium in the form of ferroniobium is used worldwide, mostly as an alloying element in …
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A review on extractive metallurgy of tantalum and niobium
On-going technological developments, especially in the field of microelectronics and communication have reflected in concomitant increase in the demand for strategic metals such as tantalum (Ta) and niobium (Nb). The extraction of these two metals from ore deposits and secondary resources is based on the generic extractive …
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Niobium and Tantalum | SpringerLink
Niobium occurs associated with tantalum in the mineral columbite [ (Fe, Mn)O. (Nb, Ta) 3 O 5 ], which has been considered the most important source of …
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Niobium/tantalum-based materials: Synthesis and …
Niobium/tantalum-based materials: Synthesis and applications in electrochemical energy storage - ScienceDirect. Chemical Engineering Journal. Volume …
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Surface superconductivity in niobium and niobium-tantalum …
Surface superconductivity in niobium and niobium-tantalum alloys. J. R. Hopkins and D. K. Finnemore. Phys. Rev. B 9, 108 – Published 1 January 1974; Erratum Phys. Rev. …
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In vitro assessment of corrosion resistance and …
The surface morphology of tantalum-niobium oxide composite thin lms coated at two different Nb concentrations is displayed in Fig. 6 . The two types of lms coated on Mg alloy show almost identical
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Chemical Profiles of the Oxides on Tantalum in State of the …
We have recently demonstrated that tantalum (Ta) based planar transmon qubits can exhibit record lifetimes over 0.3 ms and quality factors (Q) over seven million, …
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(PDF) Application of niobium and tantalum oxides for implant surface
tantalum or niobium oxide on the surface of other metals. Both lead to the metal's insulation from environmental. stress by the unbroken, durable, and at the same time elastic,
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The application of niobium and tantalum oxides for …
Received 11 October 2007; accepted 19 December 2007. 141 Model samples for the electrochemical tests were made of titanium, niobium and tantalum foils of thickness. t = 5 × 10–4 m. Relaxation of mechanical stresses in the sample bulk was achieved by vacuum annealing at pressure P = 1 × 10–3 Pa during τ = 30 min, which also cleaned and ...
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THE SURFACE ENERGIES OF SOLID MOLYBDENUM, NIOBIUM, TANTALUM, AND
A spectrophotometric method for determining 0.0005 to 0.125% of copper in high-purity niobium, tantalum, molybdenum, and tungsten metals is described.
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Vanadium, niobium and tantalum by XPS
Tools. We present high-resolution XPS spectra of elemental vanadium, niobium and tantalum sputter-cleaned by Ar + ions. The energy scales are shown without applying any corrections, and the position of the Fermi level was verified to be at zero binding energy within better than 0.1 eV, as determined from the Fermi edge …
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Niobium and tantalum
Niobium and tantalum are transition metals that are almost always found together in nature because they have very similar physical and chemical properties. Their properties …
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Quasiparticle lifetime in tantalum kinetic inductance …
have opted for tantalum, because of its demonstrated lifetime and high critical temperature. A 150 nm tantalum layer is sputter deposited onto a HF-cleaned [100] Si wafer. Prior to tantalum deposition a 5 nm niobium seed layer is sputtered to promote growth of the tantalum alpha phase [6]. -50 0 50 100 150 0.00 0.25 0.50 0.75-1 0 1-1 0 1 pulse ...
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Influence of niobium/tantalum doping on the hydrogen …
DOI: 10.1016/j.ijhydene.2022.11.110 Corpus ID: 256752970; Influence of niobium/tantalum doping on the hydrogen behavior of ZrCo(110) surface @article{Zhang2023InfluenceON, title={Influence of niobium/tantalum doping on the hydrogen behavior of ZrCo(110) surface}, author={Binjing Zhang and Xiaoqiu Ye and …
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Getter Materials
For most heat-treating applications, stainless steels and metals in Group IV of the periodic table (titanium, zirconium, hafnium) are particularly well suited as getter materials. For more sophisticated applications, tantalum, niobium, thorium and many other materials have been successfully used. The amount of gas that a getter can absorb is ...
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Synthesis of Niobium and Tantalum Nitrides via Nitridation …
The starting materials used were tantalum and niobium pentoxides manufactured at Solikamsk Magnesium Plant and also Mg 4 Ta 2 O 9 magnesium tantalate and Mg 4 Nb 2 O 9 magnesium niobate synthesized by sintering a stoichiometric feedstock oxide mixture at a temperature of 1300°C for 2 h. The pentoxides were heat-treated …
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Systematic Improvements in Transmon Qubit Coherence Enabled by Niobium
Our surface-encapsulated niobium qubit devices exhibit T$_1$ relaxation times 2 to 5 times longer than baseline niobium qubit devices with native niobium oxides. When capping niobium with tantalum, we obtain median qubit lifetimes above 300 microseconds, with maximum values up to 600 microseconds, that represent the highest …
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