skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Controlled grain boundary structures in superconductors. Annual technical report 1 January--31 December 78

Abstract

The relationship between grain boundary structure and chemistry and the critical current properties of superconductors is being investigated. The critical current (flux pinning) contributed by single grain boundaries in Nb bicrystals has been observed and shown to be suprisingly large even for boundaries that should have no crystal anisotropy or stress field contribution to the elementary interaction force between a grain boundary and the flux line lattice. Transmission electron microscopy and X-ray topography have been used to characterize the grain boundary structure and bicrystal substructure, respectively. The first high angle symmetric tilt examined is straight, shows no periodic structure and appears to be free of precipitates or detectable segregation. The electron float zone welding method of bicrystal manufacture is shown to give rise to very low angle subboundaries lying approximately parallel to the main grain boundaries. These contribute an annoyingly high background critical current which makes isolation of the main boundary contribution somewhat uncertain.

Authors:
Publication Date:
Research Org.:
Cornell Univ., Ithaca, NY (USA)
OSTI Identifier:
5854717
Alternate Identifier(s):
OSTI ID: 5854717
Report Number(s):
AD-A-067310
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; NIOBIUM; CRITICAL CURRENT; SUPERCONDUCTORS; GRAIN BOUNDARIES; ANISOTROPY; BISMUTH COMPOUNDS; CRYSTAL STRUCTURE; CURRENT DENSITY; ELECTRON MICROSCOPY; LEAD COMPOUNDS; MAGNETIC FLUX; POLYCRYSTALS; X-RAY DIFFRACTION; COHERENT SCATTERING; CRYSTALS; CURRENTS; DIFFRACTION; ELECTRIC CURRENTS; ELEMENTS; METALS; MICROSCOPY; MICROSTRUCTURE; REFRACTORY METALS; SCATTERING; TRANSITION ELEMENTS 360104* -- Metals & Alloys-- Physical Properties; 656102 -- Solid State Physics-- Superconductivity-- Acoustic, Electronic, Magnetic, Optical, & Thermal Phenomena-- (-1987)

Citation Formats

Kramer, E.J. Controlled grain boundary structures in superconductors. Annual technical report 1 January--31 December 78. United States: N. p., 1979. Web.
Kramer, E.J. Controlled grain boundary structures in superconductors. Annual technical report 1 January--31 December 78. United States.
Kramer, E.J. Thu . "Controlled grain boundary structures in superconductors. Annual technical report 1 January--31 December 78". United States.
@article{osti_5854717,
title = {Controlled grain boundary structures in superconductors. Annual technical report 1 January--31 December 78},
author = {Kramer, E.J.},
abstractNote = {The relationship between grain boundary structure and chemistry and the critical current properties of superconductors is being investigated. The critical current (flux pinning) contributed by single grain boundaries in Nb bicrystals has been observed and shown to be suprisingly large even for boundaries that should have no crystal anisotropy or stress field contribution to the elementary interaction force between a grain boundary and the flux line lattice. Transmission electron microscopy and X-ray topography have been used to characterize the grain boundary structure and bicrystal substructure, respectively. The first high angle symmetric tilt examined is straight, shows no periodic structure and appears to be free of precipitates or detectable segregation. The electron float zone welding method of bicrystal manufacture is shown to give rise to very low angle subboundaries lying approximately parallel to the main grain boundaries. These contribute an annoyingly high background critical current which makes isolation of the main boundary contribution somewhat uncertain.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1979},
month = {2}
}

Technical Report:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that may hold this item. Keep in mind that many technical reports are not cataloged in WorldCat.

Save / Share: