Comparative study of critical current density, pinning force and levitation force behavior in Yb211 doped-Sm123 bulk superconductors

The effect of Yb211 doping on the critical transition temperature (T-c), c-lattice parameter, critical current density (J(c)), volume pinning force (F-p) and the vertical levitation force density properties of MPMG-processed (Sm123)(1-x)(Yb211)(x) samples were investigated. In this study the (Sm123)(1-x)(Yb211)(x) sample with x = 0.25 shows the best J(c)(0) value which is almost five times larger than that of the undoped one at zero field and at 77 K, though in the peak effect region the best J(c) performance has the sample with x = 0.05 Yb211 doping ratio. J(c)(H) curves exhibits a wide plateau ranging from 0.75 to 2.75 T at 77 K with Yb211 doping ratio for 0.05 <= x <= 0.20 pointing out that the (Sm123)(1-x)(Yb211)(x) samples presented here are attractive for superconducting application especially under high magnetic fields. (C) 2011 Elsevier B. V. All rights reserved.