Formation of a palladium carbide with a palladium-silicide-like structure in fullerene-C-60/Pd multilayers

We present structural studies of C-60/Pd multilayer films. A new phase of a layered structure with a sixfold (or threefold) axis, which is similar to the metastable phase in Pd-Si alloys, has been observed by means of transmission electron microscope and X-ray diffraction in the C-60/Pd multilayer films after annealed at 470 K 60 min. This new phase, which is believed to be one metastable phase of Pd-C, is a hexagonal structure with the lattice constant a = 0.438 nm. The reciprocal lattice points become continuous spikes in the direction c* of the reciprocal lattice, which indicates the Pd-C phase consists of layers. (C) 2000 Elsevier Science Ltd. All rights reserved.