Flux-pinnining in Y_0.5/Nd_0.5(123) melt-textured sample

Flux-pinning in Y_0.5/Nd_0.5 (123) melt-textured growth sample that bad been doped with excess 20wt.% Y₁/Nd₁(211) and 0.5 wt.% PtO₂ has been analyzed by means of a scaling approach. The different parameters of scaling, irreversibility field (B_irr), magnetic field (B_fp) and current density(J_p) of the fishtail peak effect, and the field (B_fp) corresponding to the maximum pinning force density (F_p.max), were determined using the measurements of magnetically induced current density as a function of field and temperature. For the commonly used scaling of normalized volume pinning force, (F_p = J_cxB_a)F_pp,max, versus reduced magnetic fields h=B_a/B_irr, (where B_a stands for applied magnetic field), the curves collapse into a universal curve with a peak corresponding to h=0 44. Based on the approach of Dew-Hughes [1], we interpret the position of this peak as a clear indication of a δT_c-pinning type. Similar scaling was also obtained with the use of B_pf instead of B_irr, but poor scaling was obtained with the use of J_p. Our results are compared with those for other Re (123) systems.