The magnetization of PrFeAsO0.60F0.12 superconductor

Abstract

The magnetization of the PrFeAsO0.60F0.12 polycrystalline sample has been measured as functions of temperature and magnetic field (H). The observed total magnetization is the sum of a superconducting irreversible magnetization (Ms) and a paramagnetic magnetization (Mp). Analysis of dc susceptibility χ(T ) in the normal state shows that the paramagnetic component of magnetization comes from the Pr +3 magnetic moments. The intragrain critical current density (JL) derived from the magnetization measurement is large. The JL(H) curve displays a second peak which shifts towards the high-field region with decreasing temperature. In the low-field region, a plateau up to a field H * followed by a power law H −5/8 behavior of JL(H) is the characteristic of the strong pinning. A vortex phase diagram for the present superconductor has been obtained from the magnetization and resistivity data.

Vortex dynamics and second magnetization peak in PrFeAsO0.60F0.12 superconductor

“…Though the present sample is polycrystalline in nature, scanning electron microscope images reveal large, oriented, and well-connected plate-like crystallites. The average grain size in this sample is larger than those normally reported in oxypnictide polycrystalline samples and the plate-like grains have a tendency to orient their ab-plane along the broad face of the sample [31]. All these led us to venture for the GIS analysis on the relaxation data of our polycrystalline sample.…”

Density effect on critical current density and flux pinning properties of polycrystalline SmFeAsO1 −xFxsuperconductor

“…Another possible reason is that the weak linked areas [40] in sample B-F are suppressed or driven normal with the increment of applied fields, and they may act as pinning centers similar to the role of oxygen deficiency in YBCO [41,42]. Recently, the peak effect of J cm (B) in oxypnictide polycrystal [36] and single crystal [43] was verified to be caused by a first order phase transition from a ordered "elastically pinned" low-field vortex phase to a high-field disordered phase. weak links or local links due to Fe-As wetting phase on the grain boundary [19,25,27], and the number of strong links is very few.…”

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

“…27), and PrFeAsO 0.6 F 0.1 . 28 The observed SMP for electron and hole doped Ba-122 crystals for H//c 19 was disappeared for H//ab, indicating an anisotropic effect of flux pinning for these compounds. 19 There are two main pinning mechanisms in type II superconductors: (I) dl pinning from spatial variation in the charge carrier mean free path, l, and (II) dT c pinning due to randomly distributed spatial variation in T c .…”