Crystal phase analysis of SnO{sub 2}-based varistor ceramic using the Rietveld method

Journal Article · Fri Sep 15 00:00:00 EDT 2006 · Materials Characterization

DOI:https://doi.org/10.1016/j.matchar.2006.01.012· OSTI ID:20889848

Moreira, M L ^[1]; Pianaro, S A ^[1]; Andrade, A V.C. ^[2]; Zara, A J ^[1]

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1. Materials Engineering Department - Interdisciplinary Laboratory of Ceramic Materials, Universidade Estadual de Ponta Grossa (UEPG), Ponta Grossa - PR, CEP 84.030-900 (Brazil)
2. Physics Department, Universidade Estadual de Ponta Grossa (UEPG), Ponta Grossa - PR, CEP 84.030-900 (Brazil)

A second addition of l mol% of CoO to a pre calcined SnO{sub 2}-based ceramic doped with 1.0 mol% of CoO, 0.05 mol% of Nb{sub 2}O{sub 5} and 0.05 mol% of Cr{sub 2}O{sub 3} promotes the appearance of a secondary phase, Co{sub 2}SnO{sub 4}, besides the SnO{sub 2} cassiterite phase, when the ceramic was sintered at 1350 deg. C/2 h. 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.% SnO{sub 2} and 3 wt.% Co{sub 2}SnO{sub 4}. The microstructural analysis showed that a certain amount of cobalt ion remains into cassiterite grains.

• OSTI ID: 20889848
• Journal Information: Materials Characterization, Journal Name: Materials Characterization Journal Issue: 3 Vol. 57; ISSN 1044-5803; ISSN MACHEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CERAMICS
CHROMATES
CHROMIUM OXIDES
COBALT IONS
CRYSTALS
DOPED MATERIALS
MICROSTRUCTURE
NIOBATES
NIOBIUM OXIDES
PHASE STUDIES
SCANNING ELECTRON MICROSCOPY
TIN OXIDES
X RADIATION
X-RAY DIFFRACTION