Enhanced flux pinning in Ag-sheathed Bi(Pb)–Sr–Ca–Cu–O superconductors tapes with addition of magnetic nanorod γ-Fe2O3

Abstract

The pinning strength of the Ag-sheathed Bi(Pb)–Sr–Ca–Cu–O tapes with the addition of magnetic nanorod γ-Fe2O3 is studied using the exponent n values obtained from power law current-electric field (I-E) characteristics. The starting composition of the γ-Fe2O3 added samples is Bi1.6Pb0.4Sr2Ca2Cu3O10-(γ-Fe2O3)0.01. The rate of decrease of n values in applied fields for the tapes with nano-γ-Fe2O3 is found lower than the tapes without nano-γ-Fe2O3. This indicates that the pinning strength for the tapes with nano γ-Fe2O3 is relatively higher than the tapes prepared without nano γ-Fe2O3. The results are supported by two conventional methods which are normally used to compare the pinning strength of superconductor tapes. Magnetic impurities generally suppress superconductivity. However, our study shows that magnetic nanorod γ-Fe2O3 enhanced the pinning strength of Ag-sheathed Bi–Sr–Ca–Cu–O superconductor tapes. This is consistent with previous calculations on frozen flux superconductor with magnetic nanorod as pinning centers.

Transport critical current density of (Bi1.6Pb0.4)Sr2Ca2Cu3O10/Ag superconductor tapes with addition of nanosized CoFe2O4

“…A lower optimal amount (wt%) to optimize J c was observed when the tapes are added with magnetic nanoparticles. The optimal amount of CoFe 2 O 4 addition in this study (0.01 wt%) is similar to that of the cFe 2 O 3 -, Fe 3 O 4 -, NiFe 2 O 4 -and NiO-added tapes [17][18][19][20]. For PbO- [15] and MgO [21]-added tapes, the optimal amount is x = 0.1 wt%.…”

Enhanced Critical Current Density of FeF2 Added YBa2Cu3O7−δ

“…However, the reports showed the suppression of T c with Fe substitution (for example [3][4][5]). Addition of nanosized γ -Fe 2 O 3 and Fe 3 O 4 in Bi-Sr-Ca-Cu-O superconductors results in enhanced J c [6,7]. α-Fe 2 O 3 substitution in GdBa 2 Cu 3 O 7−δ also showed enhanced critical current density [8].…”

Growth and properties of air-processed GdBa2Cu3O7−δ superconductors with fined Gd2BaCuO5 and Gd2Ba4CuFeOy additions

“…However, there are a few reports about the contribution with the doping of M = Fe magnetic ion till now, since the magnetic ions of additions may destroy the superconductor properties of the RE123 bulk. Lau et al observed that the Ag-sheathed Bi(Pb)-Sr-Ca-Cu-O tapes with magnetic nano-powder c-Fe 2 O 3 increase the pining strength [9].…”