Microwave-assisted combustion synthesis can be used to synthesize the nano-crystalline (Ni/NiO)-YSZ composites. In this study nano-crystal line powders were prepared by combustion synthesis process in a microwave oven. The influence of pH value of the precursor solution on the combustion behavior and phase formation of synthesized powders were investigated by X-ray diffraction technique (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermal analysis (DTA/TGA), infrared (IR) spectroscopy, and BET surface area analysis. The results show that by increasing pH value, the combustion rate decreases. The as-burnt powder prepared with pH 0.5 has a higher crystallite size (32 nm). Furthermore, FTIR studies show that the glycine monodentate complex convert to bidentate complex with increasing pH. (C) 2007 Elsevier B.V. All rights reserved.