Title :
Preparation and properties of nanosize TiO/sub 2/ and MgO-doped Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub x/ tapes
Author :
Wangshui Wei ; Yangren Sun ; Schwartz, J. ; Goretta, K. ; Balachandran, U. ; Bhargava, A.
Author_Institution :
Nat. High Magnetic Field Lab., Florida State Univ., Tallahassee, FL, USA
fDate :
6/1/1997 12:00:00 AM
Abstract :
Nanosize MgO and TiO/sub 2/ particles were added to the Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub x/ powder with 20% molar fraction. Powder-in-tube Ag-sheathed tapes were made from the doped powders and heat treated by partial melting processing. Heat treatment optimization was carried out to increase the critical current density. Scanning electron microscopy and energy-dispersive X-ray spectra were used to study the phases present in the tapes. The effect of MgO additions on the flux pinning behavior was investigated by magnetic hysteresis and transport critical current measurements at various temperatures and fields.
Keywords :
X-ray chemical analysis; bismuth compounds; calcium compounds; ceramics; critical current density (superconductivity); flux pinning; heat treatment; high-temperature superconductors; magnesium compounds; magnetic hysteresis; nanostructured materials; powder technology; scanning electron microscopy; strontium compounds; superconducting tapes; titanium compounds; Ag; Bi/sub 2/Sr/sub 2/CaCu/sub 2/O:MgO; Bi/sub 2/Sr/sub 2/CaCu/sub 2/O:TiO/sub 2/; MgO-doped Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub x/ tapes; TiO/sub 2/-doped Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub x/ tapes; critical current density; doped powders; energy-dispersive X-ray spectra; flux pinning behavior; heat treatment optimization; magnetic hysteresis; nanosize MgO particles; nanosize TiO/sub 2/ particles; partial melting processing; powder-in-tube Ag-sheathed tapes; scanning electron microscopy; transport critical current measurements; Bismuth; Critical current; Critical current density; Flux pinning; Heat treatment; Magnetic hysteresis; Powders; Scanning electron microscopy; Strontium; Temperature measurement;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
