Abstract
In this data article we have presented the Rietveld refinement results of the X-ray diffraction data of both bulk and nanocrystalline La(2)Mo(2)O(9) and bulk La(2)MoWO(9) oxide ion conductors at different temperatures. Bulk and nanocrystalline La(2)Mo(2)O(9) samples were prepared by conventional solid state reaction and glycine auto ignition method, respectively. Transmission electron microscopy is also employed to determine the grain size of the sample prepared via glycine auto ignition method.