The far-infrared vibrational spectra for charged vanadium clusters as well as charged and neutral niobium clusters have been measured size specifically using farinfrared multiple photon dissociation. The ground state energy and vibrational spectra of a large number of stable and metastable structures for each of these sizes and systems have also been calculated using densityfunctional theory (D...

The study discusses the microstructure and mechanical properties of eight tested 0.3 % C -30 % Ni 18 % Cr cast steels stabilized with niobium and titanium after annealing in the cycle of 900 °C / 300 h. The niobium content in the cast steels varied from 0.0 to 2.0 % and that of titanium from 0.0 to 1.2 % by weight. Microstructure was examined using both light microscope and a scanning electron ...

Niobium and tantalum carbide clusters have been isolated in the gas phase and irradiated with intense tunable infrared (IR) light. Stable neutral clusters are selectively ionized and subsequently detected in a mass spectrometer. By tuning the IR frequency, infrared multiphoton absorption spectra are obtained for a whole range of clusters. These mass-selective IR spectra lead to insights into th...

A method to electropolish niobium with continuous current oscillation is introduced. The current continuously oscillates for as long as 3 hours. The key is to maintain continuous agitation of the acid mixture. A niobium surface treated by this method has suppressed grain boundaries and a lower hydrogen content. The method has been used to electropolish L-band half-cells. The test results of a 1...

Transient electrochemical techniques showed that in NaCI-KC1 melts the reduction of K2NbF7 occurs through a two-step reaction Nb(V) --> Nb(IV) --> Nb. When oxide ions were introduced, cyclic voltammetry indicated that the waves corresponding to reduction ol the complex NbF~progressively disappeared. Oxo complexes, such as NbOF~ n 3) , are reduced at a potential close to that of the Nb(IV) fluor...

Current superconducting cavities are generally made of solid Niobium. A possibility to reduce cost as well as increase the quality factor and/or accelerating fields is to use thin film coated cavities. Apart from Niobium thin films, other substances such as Magnesium diboride, Niobium nitride and Niobium-tin are promising candidates. Measuring the RF-properties of superconducting thin films, sp...

Interfacial fracture toughness and cyclic fatigue-crack growth properties of joints made from 99.5% pure alumina partially transient liquid-phase bonded using copper/niobium/copper interlayers have been investigated at both room and elevated temperatures, and assessed in terms of interfacial chemistry and microstructure. The mean interfacial fracture toughness, Gc, was found to decrease from 39...

A novel high-temperature synthesis of niobium oxide nanostructures has been developed through an amorphous intermediate that crystallizes into anisotropic crystalline structures through a complex mechanism of nucleation-dissolution-selective growth induced by seeded growth. The amorphous materials formed by the thermolysis of niobium oleate transformed into crystalline platelets, wires or bundl...

This Article is brought to you for free and open access by the Physics at ODU Digital Commons. It has been accepted for inclusion in Physics Faculty Publications by an authorized administrator of ODU Digital Commons. For more information, please contact [email protected]. Repository Citation Ciovati, Gianluigi and Kneisel, Peter, "Measurement of the High-Field Q Drop in the TM010 and TE011...

Superconducting radio frequency (SRF) cavities for particle accelerators are fabricated using high purity niobium to allow for continuous high power operation. A hot-spot generated at a surface defect during accelerator operation can quench superconductivity and limit its performance. Increased heat conduction to the liquid helium bath dissipates hot spots, maintaining performance. Properly tre...