Title :
Bi Addition Effect on Jc-B Performance of Powder-in-Tube Processed MgB2 Tapes
Author :
Zhang, Xianping ; Ma, Yanwei ; Gao, Zhaoshun ; Wang, Dongliang ; Yu, Zhengguang ; Awaji, Satoshi ; Watanabe, Kazuo
Author_Institution :
Chinese Acad. of Sci., Beijing
fDate :
6/1/2007 12:00:00 AM
Abstract :
MgB2 tapes with 5 at.% Bi addition were fabricated through the in situ powder-in-tube method. Heat treatment was carried out at 700degC and 800degC for 1 h. The phase, microstructure, superconductivity and flux pinning ability were characterized by XRD, SEM, magnetic and transport measurements. The critical current density Jc and Jc-B performance for the doped and undoped samples are also given. It is found that nano-Bi doping decreased the magnetic field sensitivity of Jc, indicating an improvement of flux pinning. At 4.2 K, 10 T, Jc values of the Bi doped tapes enhanced about 2.5 times compared to that of undoped samples. The mechanism for improved Jc-B performance of Bi-doped MgB2 tapes is investigated.
Keywords :
X-ray diffraction; bismuth; critical current density (superconductivity); heat treatment; magnesium compounds; scanning electron microscopy; superconducting tapes; type II superconductors; Bi addition; MgB2 tapes; MgB2:Bi; SEM; XRD; critical current density; flux pinning; heat treatment; magnetic field sensitivity; magnetic flux density 10 T; powder-in-tube processing; temperature 4.2 K; temperature 700 degC; temperature 800 degC; time 1 h; Bismuth; Flux pinning; Heat treatment; Magnetic field measurement; Magnetic flux; Microstructure; Phase measurement; Superconducting magnets; Superconductivity; X-ray scattering; ${hbox{MgB}}_{2}$; Critical current property; doping effect; microstructure;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2007.899490
