Superconducting critical currents jc>105 A/cm2 at temperatures T∼50 K and magnetic fields B∼6 T are reported for the YBa2Cu3−xMoxO7+d compound with x=0.02. Clear evidence for the increased pinning force Fp was found from a peak effect present for jc(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 Fp data as a single function of a reduced field b=B/Bk, where the scaling field Bk<<Hc2 was related to the irreversibility filed Birr. Analyses of the field dependence of jc(B,T) and Fp(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 MoO6 octahedra in the CuO chains.
@article{arxiv.cond-mat/0610067,
title = {Increase of critical currents and peak effect in Mo substituted YBa$_{2}$Cu$_{3}$O$_{7}$},
author = {K. Rogacki and B. Dabrowski and O. Chmaissem},
journal= {arXiv preprint arXiv:cond-mat/0610067},
year = {2009}
}