Electrical conductivity of Ca1-xSrxTi0.65Fe0.35O3-delta, x=0, 0.5 and 1, polycrystalline compounds in the 300-500 K range

Autor(es)

Muccillo, R. ^[1] ; Carmo, J. R. ^[1]

Afiliação do(s) autor(es)

^[1] Ctr Sci & Technol Mat, Energy & Nucl Res Inst, BR-05508900 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Materials Research Bulletin; v. 47, n. 5, p. 1204-1211, MAY 2012.
• Citações Web of Science: 3

Resumo

Bulk and grain boundary electrical conductivity of oxygen deficient CaxSr1-xTi0.65Fe0.35O3-delta, X = 0, 0.5 and 1.0, polycrystalline specimens were evaluated by impedance spectroscopy measurements in the 5 Hz-13 MHz frequency range from 300 to 500 K. The ceramic powders were synthesized by solid state reaction and by a chemical route, the polymeric precursor technique. The X-ray diffraction of the samples at room temperature shows the following perovskite crystalline structures: cubic for x = 0 and orthorhombic for x = 0.5 and 1.0. The impedance plots are composed of two semicircles ascribed to grains (bulk) and interfaces (grain boundaries) contributions. The impedance data show that sintered pellets using powders prepared by solid state synthesis present higher intergranular and intragranular resistivity values than pellets prepared by the chemical route. Observations of scanning probe microscopy topographic images of the surfaces of the sintered pellets show evident differences between the grain morphology of the pellets prepared with powders synthesized by the two routes. (C) 2012 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 05/53241-9 - Estudo de fenômenos intergranulares em materiais cerâmicos
• Beneficiário: Reginaldo Muccillo
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 98/14324-0 - Multidisciplinary Center for Development of Ceramic Materials
• Beneficiário: Elson Longo da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs
• Processo FAPESP: 95/05172-4 - Laboratório de análise térmica de materiais cerâmicos metálicos e compósitos
• Beneficiário: Reginaldo Muccillo
• Modalidade de apoio: Auxílio à Pesquisa - Programa Infraestrutura - Equipamentos