Please use this identifier to cite or link to this item: http://www.repositorio.ufc.br/handle/riufc/46613
Title in Portuguese: Microstructural and electrical properties of sintered tungsten trioxide
Title: Microstructural and electrical properties of sintered tungsten trioxide
Author: Matias, João Guilherme Nogueira
Keywords: Dielectric constant
Electrical resistivity
Reduction process
Capacitance measurement
Monoclinic phases
Issue Date: 1999
Publisher: Journal of materials science
Citation: MATIAS, J. G. N.
Abstract: Tungsten trioxide sintered wafers were prepared from WO3 powder obtained when ammonium paratungstate is decomposed in air at moderate temperature. Two wafer series of five samples were sintered under the same conditions in the temperature range 600–1000 C. One of these wafers series was submitted to a subsequent annealing at 700 C under a hydrogen atmosphere. All samples were characterized at room temperature by X-ray diffraction and electrical measurements. X-ray spectra show that WO3 ceramic presents a mixture of the triclinic and monoclinic phases before the reduction process. After the reduction process, WO2 and four hydrogen tungsten bronze phases are present in wafers. Capacitance measurements showed that the samples submitted only to the sintering process changed the dielectric constant with the frequency according to the Debye model. The reduced WO3 shows a semiconductor behavior, as determined by electrical resistivity measurements.
Description: MATIAS, J. G. N. Microstructural and electrical properties of sintered tungsten trioxide. 1999. Artigo (Journal of materials science), 1999.
URI: http://www.repositorio.ufc.br/handle/riufc/46613
metadata.dc.type: Artigo de Periódico
Appears in Collections:CSOBRAL - Artigos publicados em revistas científicas

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