We report ac susceptibility data on RuSr_2(Eu,Ce)_2Cu_2O_(10-y) (Ru-1222, Ce content x=0.5 and 1.0), RuSr_2GdCu_2O_8 (Ru-1212) and SrRuO_3. Both Ru-1222 (x=0.5, 1.0) sample types exhibit unexpected magnetic dynamics in low magnetic fields: logarithmic time relaxation, switching behavior, and `inverted' hysteresis loops. Neither Ru-1212 nor SrRuO_3 exhibit such magnetic dynamics. The results are interpreted as evidence of the complex magnetic order in Ru-1222. We propose a specific multilayer model to explain the data, and note that superconductivity in the ruthenocuprate is compatible with both the presence and absence of the magnetic dynamics.
@article{arxiv.cond-mat/0110181,
title = {Ruthenocuprates RuSr2(Eu,Ce)2Cu2O10: Intrinsic magnetic multilayers},
author = {I. Zivkovic and Y. Hirai and B. H. Frazer and M. Prester and D. Drobac and D. Ariosa and H. Berger and D. Pavuna and G. Margaritondo and I. Felner and M. Onellion},
journal= {arXiv preprint arXiv:cond-mat/0110181},
year = {2009}
}
Comments
9 pages, 11 figures, Revtex; submitted to Phys.Rev.B