Solid-hexatic-liquid transition in a two-dimensional system of charged dust particles O. F. Petrov, M. M. Vasiliev, O. S. Vaulina, K. B. Stacenko, E. V. Vasilieva, E. A. Lisin, Y. Tun and V. E. Fortov EPL, 111 4 (2015) 45002 Published online: 08 September 2015 DOI: 10.1209/0295-5075/111/45002