Studies on the structural, quantitative and semi-quantitative analyses of NiO-GDC nanocomposites

A simultaneous analysis of the crystallite size and strain of xNiO·(1 - x)GDC nanopowders prepared in stoichiometric proportions of x = 0, 0.1, 0.2... to 1 was performed by a self-sustained combustion (SC) process and calcination of the thus-synthesized nanopowders at 600 °C. The nanopowders were examined by powder X-ray diffraction (XRD) pattern using two approaches: integral breadth of multiple peaks (multi-line) with Pearson VII (PVII), and pattern analysis of powders through total adjustment of the diffraction peaks with the double-Voigt (V-V) method. The synthesis route and stoichiometric variation allowed a quantitative study using the global setting profile with Rietveld refinement and semi-quantitative analysis by X-ray fluorescence (XRF) of nickel oxide (NiO) and gadolinium doped ceria (GDC) phases in the as-prepared and the calcined samples. The investigation of the microstructures of the nanopowders was further supported by high-resolution transmission electron microscopy (HR-TEM) and scanning electronic microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS).