La2CoMnO6-delta crystal doped with Pb and Pt was successfully grown. The lattice parameters were determined by X-ray diffractometry, while polarized Raman spectroscopy and magnetic measurements were used to probe the Co/Mn positional order, and to suggest the most likely crystal and magnetic structures. The magnetic response of the crystal to ac- and dc-magnetic fields is discussed in terms of possible occupation of the crystallographic positions by the constituent ions and valence state disproportion in the Mn/Co ions. The results are explained within a framework of statistically random distributed Mn3+-O-Mn4+ and Co2+-O-Pt4+ chains within the predominantly ordered Co2+/Mn4+ double perovskite structure. (C) 2012 Elsevier Ltd. All rights reserved.