Plasma spray synthesis of ultra-fine YSZ powder

A plasma spray process has been developed for the mass production of nanopowders for solid oxide fuel cells (SOFCs) and significant technical developments have been achieved during the past 2 years. Ultra-fine powders of 8 mol% yttria-stabilized zirconia (YSZ) were produced directly from a precursor solution via plasma spray process. The powders were characterized by X-ray diffraction (XRD), nitrogen absorption technique (BET), transmission electron microscopy (TEM), particle size analysis (PSA), and thermogravimetric analyses (TG). The as-sprayed YSZ powders with cubic phase were obtained without obvious impurity species. BET surface area of the sprayed powder reached as high as 27 m(2) g(-1), indicating an equivalent particle size of 37 nm. The powder showed mostly spherical with mean size of about 100-200 nm by TEM results. Introduction of an organic additive resulted in a significantly increased specific surface area, accompanied by a slight decrease in grain size. This plasma spray process has the potential to be a less costly and time saving one for nanopowder production than the existing wet chemistry processes. (C) 2007 Elsevier B.V. All rights reserved.