Increase of critical currents and peak effect in Mo substituted YBa$_{2}$Cu$_{3}$O$_{7}$

K. Rogacki; B. Dabrowski; O. Chmaissem

doi:10.1103/PhysRevB.73.224518

paper

Increase of critical currents and peak effect in Mo substituted YBa $_{2}$ Cu $_{3}$ O $_{7}$

arXiv:cond-mat/0610067 · doi:10.1103/PhysRevB.73.224518

Abstract

Superconducting critical currents $j_{c} > 1 0^{5}$ A/cm $^{2}$ at temperatures $T \sim 50$ K and magnetic fields $B \sim 6$ T are reported for the YBa $_{2}$ Cu $_{3 - x}$ Mo $_{x}$ O $_{7 + d}$ compound with $x = 0.02$ . Clear evidence for the increased pinning force $F_{p}$ was found from a peak effect present for $j_{c} (B)$ . The pinning force was analyzed by a scaling procedure using Kramer's approach. For a wide range of fields and temperatures, we were able to express all $F_{p}$ data as a single function of a reduced field $b = B / B_{k}$ , where the scaling field $B_{k} << H_{c 2}$ was related to the irreversibility filed $B_{i r r}$ . Analyses of the field dependence of $j_{c} (B, T)$ and $F_{p} (b)$ show that the effective pinning centers act as weakly interacting extended point-like defects. We propose that the pinning centers are randomly distributed small defects, most likely the dimers of MoO $_{6}$ octahedra in the CuO chains.

12 pages, 11 figures

Increase of critical currents and peak effect in Mo substituted YBa2​Cu3​O7​

Abstract

Increase of critical currents and peak effect in Mo substituted YBa $_{2}$ Cu $_{3}$ O $_{7}$