Enhancement of flux pinning in (Bi, Pb)-2223/Ag tapes doped with MgO nanorods

Abstract

MgO nanorods with an average diameter of 30 nm and lengths of 2-3 µm have been incorporated into (Bi, Pb)-2223/Ag tapes. X-ray diffraction analysis shows that a small addition of MgO nanorods does not obstruct the formation of (Bi, Pb)-2223 phase. Scanning electron microscopy images show that the size of the (Bi, Pb)-2223 grains and the degree of texture in the samples doped with 1 wt% of MgO nanorods are improved. Transmission electron microscopy observation also shows that the MgO nanorods do not agglomerate or grow during the sintering process. The transport critical current densities of the samples doped with 1 wt% of MgO nanorods are enhanced noticeably at high temperatures and magnetic fields and the irreversibility line of the samples doped with 1 wt% of MgO nanorods shifts to higher temperatures and magnetic fields as compared with the undoped samples. The possible pinning mechanism of the samples doped with MgO nanorods is discussed. The results reveal that the introduction of MgO nanorods as columnar defects can effectively enhance the flux pinning.

Electrical Transport Properties of (Bi1.6Pb0.4Sr2Ca2Cu3O10)/Ag Tapes with Different Nanosized MgO

“…Particles size (20 nm) which is closer to the coherence length (2.9 nm) is more effective in increasing . Previous reports on nano MgO addition in (Bi, Pb)-2223 pellets and tapes also showed improvement in [13,14]. In this work we showed that for low MgO content, the size of the nanoparticles also affected the .…”

“…In previous reports, MgO nanoparticles and nanorods (with average diameter of 30 nm) have been added into (Bi,Pb)-2223/Ag tapes [13,14]. MgO is chemically inert with (Bi, Pb)-2223, and the transition temperature did not change considerably with MgO content.…”

“…MgO is chemically inert with (Bi, Pb)-2223, and the transition temperature did not change considerably with MgO content. In those reports, nanosized MgO additions into (Bi, Pb)-2223/Ag tapes have only been carried out with one average size [13,14]. It is interesting to investigate the effect of different nanosized MgO on the critical current density of the (Bi, Pb)-2223 system.…”

Novel Phases of Vortices in Superconductors

“…as nanorods. 94 Their effect can even be increased by introducing a small dispersion in their direction along the c-axis, leading to the splay glass phase, 95 where localization and entanglement effects were predicted and observed 96 to conspire to a slowdown in the creep relaxation. Correlated disorder is developed in Sec.…”

Enhanced flux pinning in (Bi, Pb)-2223/Ag tapes by slight Pr substitution

“…(Bi, Pb)-2223/Ag tapes are still prevented from applications at high temperatures by their weak flux pinning. In order to enhance their flux pinning properties and improve their transport capabilities, many attempts have been made to introduce artificial defects of a nanometre order of magnitude into them as extra effective centres under an applied field, such as by heavy-ion irradiation [1][2][3][4], by nano-particles or rod doping [5][6][7] or by post annealing [8,9]. It has recently been reported that Pr substitutions for Ca may induce some normal-like defects in the Bi 2 Sr 2 CaCu 2 O y (Bi-2212) system [10].…”