Crystal growth of novel lanthanide-containing platinates K4[Ln6Pt2O15] (Ln = La, Pr, Nd, Sm) with a unique framework structure.

Crystals of a new family of lanthanide-containing platinum oxides with a unique framework structure were grown out of molten hydroxide fluxes. The structure consists of a crystallographically well-behaved [Ln(6)Pt(2)O(15)](4-) framework permeated by channels filled with disordered atoms along the [100] and equivalent directions. Open-channel structures are rare in oxides and apparently unknown in platinate chemistry.