Clusters of charged diamagnetic particles levitating in nonuniform magnetic fieldS. F. Savin, L. G. D'yachkov, M. M. Vasiliev, O. F. Petrov and V. E. FortovEPL, 88 6 (2009) 64002DOI: https://doi.org/10.1209/0295-5075/88/64002