Processing and characterisation of a fine nickel oxide/zirconia/composite prepared by polymeric complex solution synthesis

A homogeneous dispersion of nickel in a YSZ ceramic matrix by the polymeric organic complex solution method was achieved. A YSZ powder was added to the polymeric gel containing Ni2+ cations leading to an organic resin in which the YSZ particles were embedded. By further heat treatment a composite of ultrafine nickel oxide dispersed in the YSZ matrix was attained. After sintering and reducing treatment of nanocrystalline NiO/YSZ composite, the microstructure of the Ni/YSZ cermet showed a uniform distribution of the porous metallic Ni particles of about 1–2 μm surrounded by a microporous space. The electrical properties of NiO/YSZ (55/45 wt.%) composites were studied using impedance spectroscopy in the temperature range from 100 to about 700 °C. Variations in activation energy were in agreement to the NiO electrical behaviour with increasing temperatures for polymer complex solution NiO/YSZ prepared composite, which indicates a uniform and fine-grained microstructure, in which the YSZ–YSZ and/or the NiO–NiO particle contacts were predominant.