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Superconducting Properties (superconducting + property)

Distribution by Scientific Domains

Polymers and Materials Science	75%

Selected Abstracts

Growth of Thick MgB2 Films by Impinging-Jet Hybrid Physical-Chemical Vapor Deposition,

ADVANCED MATERIALS, Issue 2 2008
R. Lamborn
Thick MgB2 films are grown using a novel impinging-jet hybrid physical-chemical vapor deposition process. An increased amount of the boron source gas generates high growth rates. Superconducting properties of the thick films are comparable to previous results from other processes, which indicate that this is a promising new process for MgB2 deposition for coated conductor applications, such as wires and tapes for MRI magnets. [source]

Progress in Nanoengineered Microstructures for Tunable High-Current, High-Temperature Superconducting Wires,

ADVANCED MATERIALS, Issue 3 2008
G. Holesinger
Abstract High critical current densities (Jc) in thick films of the Y1Ba2Cu3O7,, (YBCO, Tc , 92 K) superconductor directly depend upon the types of nanoscale defects and their densities within the films. A major challenge for developing a viable wire technology is to introduce nanoscale defect structures into the YBCO grains of the thick film suitable for flux pinning and the tailoring of the superconducting properties to specific, application-dependent, temperature and magnetic field conditions. Concurrently, the YBCO film needs to be integrated into a macroscopically defect-free conductor in which the grain-to-grain connectivity maintains levels of inter-grain Jc that are comparable to the intra-grain Jc. That is, high critical current (Ic) YBCO coated conductors must contain engineered inhomogeneities on the nanoscale, while being homogeneous on the macroscale. An analysis is presented of the advances in high-performance YBCO coated-conductors using chemical solution deposition (CSD) based on metal trifluoroacetates and the subsequent processing to nano-engineer the microstructure for tuneable superconducting wires. Multi-scale structural, chemical, and electrical investigations of the CSD film processes, thick film development, key microstructural features, and wire properties are presented. Prospects for further development of much higher Ic wires for large-scale, commercial application are discussed within the context of these recent advances. [source]

Preparation and Characterization of a Large-Scale YBa2Cu3O7,x Superconductor Prepared by Plastic Forming without a High-Pressure Molding: Effect of Polyvinyl Alcohol (PVA) Addition on the Superconducting Properties

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 3 2009
Makoto Takahashi
The preparation of large-scale YBa2Cu3O7,x superconductor samples was investigated. This method is based on plastic forming using a slurry consisting of YBa2Cu3O7,x particles and a sol solution made up of multimetallic hydroxide particles (YBa2Cu3(OH)x colloidal particles) and poly(vinyl) alcohol (PVA). The effects of adding PVA on the product, the crystallinity, and the superconducting properties of the sample were investigated. It was found that PVA acted as a protective colloid in the sol solution and stabilized YBa2Cu3(OH)x colloidal particles, and that the role of PVA changed from a thickener to a flocculant during drying so that the formability/workability of the green sheet sample was improved and large samples (about 80 mm × 80 mm × 3 mm) without large cracks were obtained after firing. The samples became superconducting at 91.5±0.5 K (Tcon) and the full transition temperature (Tcoff) was 88.5±1.5 K. The critical current density (Jc) of the sample prepared from the slurry containing 1 wt% PVA was 713±150 A/cm2 at 77 K. This Jc value was improved to 2300 A/cm2 by heat treatment at 773 K under an oxygen atmosphere. [source]

The influence of mechanical alloying on the structural and physical properties of YNi4B compound

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 1 2003
M. Timko
Abstract We have investigated the influence of mechanical milling on structural changes, magnetic and superconducting properties of YNi4B compound. This compound crystallizes in a hexagonal structure with the P6/mmm space group. Magnetic measurements have shown that originally prepared sample exhibits superconducting behaviour below 12 K and above this temperature the sample is paramagnetic. The great decrease of intensity and broadening of diffraction lines have been detected after milling as a consequence of sample amorphisation. [source]