Multiple magnetization peaks in weakly pinnedCa3Rh4Sn13

Abstract

The second magnetization peak and the peak effect anomaly coexisting in a given isothermal magnetization hysteresis loop show striking similarities in Ca 3 Rh 4 Sn 13 , a low-T c superconductor and YBa 2 Cu 3 O 7Ϫ␦ , a high-T c superconductor. The observed variation of the hysteresis width with field could imply a modulation in the degree of the plastic deformation of the elastic vortex solid. The characteristics of the high-T c cuprates, such as large Ginzburg number, short coherence length, decoupling of the Josephson coupled pancake vortices, etc., are unlikely to be the cause of the observed behavior.

Flux pinning mechanism in BaFe1.9Ni0.1As2 single crystals: Evidence for fluctuation in mean free path induced pinning

“…In our case, h max ¼ 0.4, indicating that point pinning alone cannot explain the pinning mechanism in the BaFe 1. 9 23 In the case of BaFe 1.8 Co 0.2 As 2 , a peak at h max % 0.45 was suggested to be related to the inhomogeneous distribution of Co ions. 31 In particular, the fact that, in our case, the maximum in F p occurs at h < 0.5 indicates that the pinning centres in BaFe 1.9 Ni 0.1 As 2 are of the dl type, while for dT c pinning, it is expected that the maximum would occur at h > 0.5.…”

“…In conventional low temperature superconductors, e.g., MgB 2 , 7 Nb 3 Sn, 8 etc., SMP corresponds to a hump feature in J c (B) far below the B c2 while peak effect (PE) is realized to happen near B c2 . 9 It is suggested that the PE is associated with the rapid softening of the flux line lattice. 10 In high temperature superconductors, different mechanisms including inhomogeneity of the sample, 11 Dynamic effects, 12 structural phase transition in the vortex lattice, 13 vortex order-disorder phase transition, 14,15 and cross over from elastic to plastic creep 16 have been proposed to explain the SMP.…”

“…9 Ni 0.1 As 2 superconducting crystals have been investigated systematically by magnetic measurements up to 13 T at various temperatures. The field dependence of the critical current density, J c , was analysed within the collective pinning model.…”

“…A remarkably good agreement between the experimental results and theoretical dl pinning curve is obtained, which indicates that pinning in BaFe 1. 9 Ni 0.1 As 2 crystal originates from spatial variation of the mean free path. Moreover, the normalized pinning force density, F p , curves versus h ¼ B/B irr (B irr is the irreversibility field) were scaled using the Dew-Hughes model.…”

Unveiling of Bragg glass to vortex glass transition by an ac driving force in a single crystal of Yb3Rh4Sn13

“…Owing to the possibility of a sudden proliferation of dislocations on progressively increasing the magnetic field at a constant temperature, the quasi -long range ordered BG phase is anticipated [1,2] to transform first into a multi -domain (partially disordered) vortex glass (VG) phase. Such a transition usually reflects as a second peak in (isothermal) magnetization (M -H) loops, termed as the second magnetization peak (SMP) anomaly [5][6][7][8][9][10][11]. Thereafter, at elevated fields closer to the upper critical field (H c2 (T )), there occurs another anomaly, known as the quintessential peak effect (PE) phenomenon [3,9,10,[12][13][14][15][16][17][18] in field/temperature variation in critical current density, j c (H, T ).…”