Hysteresis in small arrays of interacting magnetic nanoparticles C. Xu, P. M. Hui, L. F. Zhang, Y. Q. Ma, J. H. Zhou and Z. Y. Li Eur. Phys. J. B, 46 4 (2005) 475-480 Published online: 07 September 2005 DOI: 10.1140/epjb/e2005-00283-3