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Turbostratically disordered tungsten diselenide (WSe2) thin films with as few as two c-axis-oriented (basal plane) structural units were synthesized from modulated elemental reactants. By varying t...

We describe here a general synthesis approach for the preparation of new families of misfit layer compounds and demonstrate its effectiveness through the preparation of the first 64 members of the [(PbSe)0.99]m(WSe2)n family of compounds, where m and n are integers that were systematically varied from 1 to 8. The new compounds [(PbSe)1+y]m(WSe2)n were synthesized by annealing reactant precursors containing m layers of alternating elemental Pb and Se followed by n layers of alternating elemental W and Se, in which the thickness of each pair of elemental layers was calibrated to yield a structural bilayer of rock salt structured PbSe and a trilayer of hexagonal WSe2. The compounds are kinetically trapped by the similarity of the composition profiles and modulation lengths in the precursor and the targeted compounds. The structural evolution from initial reactant of layer elements to crystalline misfit layer compounds was tracked using X-ray diffraction. The crystal structures of new compounds were probed us...

The novel, partially filled compounds CexCo4Ge6Se6 were synthesized using two methods: low-temperature interdiffusion and nucleation of ultrathin elemental layers and a bulk, high-temperature technique. The compounds were characterized by differential scanning calorimetry, powder X-ray diffraction, and electron probe microanalysis. The lattice parameters for the samples synthesized using the high-temperature technique were calculated to be 8.30 A, while the samples synthesized using the elemental deposition technique showed lattice expansion proportional to the amount of incorporated rare earth element, with lattice parameters ranging from 8.30 A for x = 0 up to a lattice parameter of 8.34 A for x = 0.2. Rietveld analysis on X-ray diffraction data for both sets of samples showed incorporation of the rare earth element into the interstitial site, up to 20% occupancy.