Cluster spin glass and superparamagnetism in RuSr2Eu1.5Ce0.5Cu2O10-δ R. Nigam, A. V. Pan and S. X. Dou Eur. Phys. J. B, 74 4 (2010) 429-436 Published online: 24 March 2010 DOI: 10.1140/epjb/e2010-00102-x