Crystal phase analysis of SnO2-based varistor ceramic using the Rietveld method
نویسنده
چکیده
A second addition of lmol% of CoO to a pre calcined SnO2-based ceramic doped with 1.0mol% of CoO, 0.05mol% of Nb2O5 and 0.05mol% of Cr2O3 promotes the appearance of a secondary phase, Co2SnO4, besides the SnO2 cassiterite phase, when the ceramic was sintered at 1350°C/2h. This was observed using X-ray powder diffraction, scanning electron microscopy and energy dispersive X-ray techniques. Rietveld refinement was carried out to quantify the phases present in the ceramic system. The results of the quantitative analysis were 97 wt.% SnO2 and 3 wt.% Co2SnO4. The microstructural analysis showed that a certain amount of cobalt ion remains into cassiterite grains. © 2006 Elsevier Inc. All rights reserved.
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