Flux pinning and flux creep in uranium-doped (Bi, Pb)-Sr-Ca-Cu-O superconducting powders after thermal-neutron irradiation

• Published in: IEEE Transactions on Magnetics (Institute of Electrical and Electronics Engineers); (United States) 1991-03, Vol.27 (2), p.1375-1378
• Main Authors: Hart, H.R., Luborsky, F.E., Arendt, R.H., Fleischer, R.L., Tkaczyk, J.E., Orsini, D.A.
• Format: Article
• Language: English
• Subjects: 360204 > Ceramics, Cermets, & Refractories-- Physical Properties; ACTINIDE COMPOUNDS; ALKALINE EARTH METAL COMPOUNDS; BARYONS; Bismuth; BISMUTH COMPOUNDS; BISMUTH OXIDES; CHALCOGENIDES; Condensed matter: electronic structure, electrical, magnetic, and optical properties; COPPER COMPOUNDS; CREEP; Critical current density; CURRENT DENSITY; DAMAGE; DOPED MATERIALS; ELEMENTARY PARTICLES; Exact sciences and technology; FERMIONS; Flux pinning; HADRONS; HYSTERESIS; IRRADIATION; LEAD COMPOUNDS; MAGNETIC FIELDS; MAGNETIC FLUX; Magnetic hysteresis; MAGNETIC PROPERTIES; Magnetization; MAGNETOMETERS; MATERIALS; MATERIALS SCIENCE; MEASURING INSTRUMENTS; MECHANICAL PROPERTIES; NEUTRONS; NUCLEONS; OXIDES; OXYGEN COMPOUNDS; PHYSICAL PROPERTIES; Physics; POWDERS; Properties of type I and type II superconductors; Strontium; STRONTIUM COMPOUNDS; Superconductivity; THERMAL NEUTRONS; TRANSITION ELEMENT COMPOUNDS 360206 > Ceramics, Cermets, & Refractories-- Radiation Effects; URANIUM COMPOUNDS; Vibration measurement
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/20.133440

Fission fragment damage was introduced into uranium-doped powdered Bi/sub 1.7/Pb/sub 0.3/Sr/sub 2/Ca/sub 2/Cu/sub 3/ O/sub y/ by irradiation with thermal neutrons. Measurements of magnetic hysteresis and flux creep were made using a vibrating sample magnetometer. Magnetic hysteresis and intragranular critical current densities, obtained from the magnetic hysteresis using the critical state model, show an increase upon irradiation of a factor of 70 at 50 K and 0.8 T. Flux creep data, interpreted as nonlinear relations between pinning energy and magnetization, as temperature-dependent pinning energies, or as distributions of pinning energies, show significant increases in pinning energy upon irradiation. The irreversibility line is found to shift to higher magnetic fields upon irradiation. It is concluded that the increase in flux creep and decrease in critical current density at higher temperatures appear to limit the potential utility of this family of oxide superconductors to the lower-temperature regime.