Magnetization analysis of sintered Bi2223 using an extended critical state model

Abstract

The field dependence of the magnetization was measured for sintered Bi2223 high Tc superconductor under a field amplitude of 5 T from 10 to 90 K. These data were analysed using our critical state model involving an equilibrium magnetization Meq and exponential decay of Jc. Some magnetic parameters including the equilibrium critical current density were determined for the intra-grain and inter-grain parts. The temperature dependences of the intra-grain and inter-grain Jc were also discussed. It was revealed that single vortex pinning was dominant in the intra-grain part, and flux creep caused by collective pinning was confirmed in the inter-grain part.

Intrinsic pinning properties of FeSe0.5Te0.5

“…In this report, we analyze J c from B⊥c-axis magnetization with extended critical state model by Kimishima [9][10][11] based on the well-known Kim model [15] and Bean model [16]. In this model the value of the internal critical current density …”

“…Here, we report the intrinsic pinning properties of FeSe 0.5 Te 0.5 , which is the superconductor with T c of about 14 K, were studied by the analysis of magnetization curves by the extended critical state model by Kimishima [9][10][11].…”

Complete flux jump in bulk MgB2 sintered under high pressure

“…By the least square fitting of our M(H)-equations [24,26,27] to the smoothed M(H)-data in Figs. 3-6 shown by the dotted lines, the characteristic parameters of B Ã eq , B 0 and J c -values in Table 1 were determined.…”

Magnetization asymmetry of type-II superconductors in high magnetic fields

“…1,2 At temperatures higher than ϳ10 K the high-field M͑H͒ dependencies of high-T c superconductors have a pronounced asymmetry with respect to the M = 0 axis, so the main parts of hysteretic loops locate in the second and the fourth quadrants. [8][9][10][11] However, some aspects of the extended critical state model, e.g., presence of the surface equilibrium layer, were questionable from experimental point of view. The critical state model was subjected to modifications to treat the asymmetric M͑H͒ dependencies.…”