Microstructural evolution with temperature of spherical zinc oxide microcrystals produced by spray pyrolysis

Abstract The microstructural evolution with temperature of zinc oxide spherical particles obtained by spray pyrolysis, has been analysed by electron microscopy, X-ray diffraction and IR spectroscopy. The initial powder composed of primary spherical particles in different agglomeration arrangements, becomes more ordered by sintering at about 875°C. The new particles (secondary particles) sinter at still higher temperatures giving a powder with poorly defined morphology. The results obtained allow one to propose a schematic representation for the different steps followed by the powder, with particular emphasis on the agglomeration state of the particles.