| Full text | |
| Author(s): |
Total Authors: 2
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| Affiliation: | [1] Ctr Sci & Technol Mat, Energy & Nucl Res Inst, BR-05508900 Sao Paulo - Brazil
Total Affiliations: 1
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| Document type: | Journal article |
| Source: | Materials Research Bulletin; v. 47, n. 5, p. 1204-1211, MAY 2012. |
| Web of Science Citations: | 3 |
| Abstract | |
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) | |
| FAPESP's process: | 05/53241-9 - Study of intergranular phenomena in ceramic materials |
| Grantee: | Reginaldo Muccillo |
| Support Opportunities: | Research Projects - Thematic Grants |
| FAPESP's process: | 98/14324-0 - Multidisciplinary Center for Development of Ceramic Materials |
| Grantee: | Elson Longo da Silva |
| Support Opportunities: | Research Grants - Research, Innovation and Dissemination Centers - RIDC |