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 mum 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 degreesC. 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. (C) 2003 Elsevier Science Ltd. All rights reserved.