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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Low-voltage, high current dc-ac converter from magnetoresistor, superconductor, Hall effect, or thin-film devices
Ti-Nb microstructural quantitative examination to determine heat treatment and plastic deformation effects on current density and other superconductor parameters
Anderson model to obtain transition metal impurities effect on superconductors due to resonance scattering
Tensile stress effect on critical current-carrying capacity of niobium-zirconium wire and niobium-tin ribbon superconductors at liquid helium temperature
Properties of high field superconductors at high temperatures - magnetization experiments on niobium and niobium compounds
Field distribution in hard superconductor with adiabatic field change
Magnetic flux flow and superconductor stabilization
Absorption dependence of ultrasonic waves in superconductors on amplitude of sound wave due to temperature
Flux jumps in hard superconductor AC and DC MAGNETIC fields
Pinning fluxoids by spatial inhomogeneities of Tl-Pb and Pb-In alloys, noting I-H CHARACTERISTICS and type II superconductor resistance
Low temperature deuteron irradiation effect on type II superconductors noting atomic displacement, resistivity increase and transition temperature decrease
Limited instability and flux jumping variation with magnetic field for flux pinning and Lorentz forces equilibrium in mixed state of type II SUPERCONDUCTOR
Linear current-voltage characteristics in type II SUPERCONDUCTORS under flux flow conditions
This paper examines photoemission measurements of the alkaline Earth core levels of high-temperature superconductors and related materials, models that seek to explain the large negative shifts observed relative to the corresponding alkaline Earth metals, and the effect of lattice site disorder on the core level spectra and the presence or absence of intrinsic surface peaks.
This report, concluding a one-year NIAC Phase I study, describes a new structural and mechanical technique aimed at reducing the mass and increasing the deployed-to-stowed length and volume ratios of spacecraft systems. This technique uses the magnetic fields generated by electrical current passing through coils of high‐temperature superconductors (HTSs) to support spacecraft structures and deploy them to operational configurations from their stowed positions inside a launch vehicle fairing.
We report scanning tunneling spectroscopic studies of the effects of quantum impurities in cuprate superconductors.
Tunneling Andreev reflection (TAR) spectroscopy provides a new approach to identify superconducting pairing symmetry at the atomic scale. Using atomistic superconducting transport simulations, we reveal the mechanism by which TAR can distinguish between pairing symmetries, which is complementary to traditional conductance-based techniques. In particular, owing to the additivity of the excess tunneling decay rate, the TAR spectrum is a weighted average of the contributions from quasiparticle currents, Andreev reflection, and higher-order scattering processes, and their relative weights depend on both the superconducting order parameter and the coupling strength. Within the local tunneling model, TAR dominates mid-gap conductance for s-wave superconductors, is suppressed for d-wave, and coexists with quasiparticle tunneling in sign-changing symmetries if the expectation value for the superconducting gap remains finite. Meanwhile, higher-order processes generally enhance the TAR signal when GN exceeds approximately 0.1G0. As a result, TAR provides a rich spectral fingerprint of the underlying pairing symmetry and electronic structure, enabling atomically resolved identification of unconventional superconducting states.
A high-throughput screening using density functional calculations is performed to search for stable boride superconductors from the existing materials database. The workflow employs the fast frozen-phonon method as the descriptor to evaluate the superconducting properties quickly. Twenty-three stable candidates were identified during the screening. The superconductivity was obtained earlier experimentally or computationally for almost all found binary compounds. Previous studies on ternary borides are very limited. Here our extensive search among ternary systems confirmed superconductivity in known systems and found several new compounds. Among these discovered superconducting ternary borides, TaMo 2 B 2 shows the highest superconducting temperature of ∼12 K. Most predicted compounds were synthesized previously; therefore, our predictions can be examined experimentally. Our work also demonstrates that the boride systems can have diverse structural motifs that lead to superconductivity.