Microstructural and nonohmic properties of ZnO.Pr6O11 CoO polycrystalline system
The microstructure and electrical properties of varistors composed of (95-x) ZnO + x Pr6O11 + 5 CoO (ZPC), (x = 0.1, 0.5 and 1.0) and sintered at 1300 and 1350 °C, were investigated. According to X-ray diffraction, several phases (ZnO, Pr2O3 and Pr2CoO4) are present when x = 1.0. Using Scanning Elec...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol)
2010-03-01
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| Series: | Materials Research |
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| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392010000100008 |
| _version_ | 1818311541252947968 |
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| author | Miguel Angel Ramírez José Francisco Fernández José de Frutos Paulo Roberto Bueno Elson Longo José Arana Varela |
| author_facet | Miguel Angel Ramírez José Francisco Fernández José de Frutos Paulo Roberto Bueno Elson Longo José Arana Varela |
| author_sort | Miguel Angel Ramírez |
| collection | DOAJ |
| description | The microstructure and electrical properties of varistors composed of (95-x) ZnO + x Pr6O11 + 5 CoO (ZPC), (x = 0.1, 0.5 and 1.0) and sintered at 1300 and 1350 °C, were investigated. According to X-ray diffraction, several phases (ZnO, Pr2O3 and Pr2CoO4) are present when x = 1.0. Using Scanning Electron Microscopy, all of these compositions contain precipitates. These phases are important regarding the development of the microstructure and the electrical properties. The samples with x = 0.1 introduce the best nonohmic behavior (α = 9.0), however when x = 0.5 the electrical properties are highly degraded due to the small quantity of effective barriers. The density of superficial states N IS and donor concentration Nd decreases with Pr6O11 addition. The decrease in the donor concentration is attributed to the annihilation of the donor defects according to the transformation of praseodymium oxides from Pr6O11 to Pr2O3. |
| first_indexed | 2024-12-13T08:03:36Z |
| format | Article |
| id | doaj.art-bae5a67f562b4804a3e3001f4404bc4c |
| institution | Directory Open Access Journal |
| issn | 1516-1439 |
| language | English |
| last_indexed | 2024-12-13T08:03:36Z |
| publishDate | 2010-03-01 |
| publisher | Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol) |
| record_format | Article |
| series | Materials Research |
| spelling | doaj.art-bae5a67f562b4804a3e3001f4404bc4c2022-12-21T23:54:21ZengAssociação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol)Materials Research1516-14392010-03-01131293410.1590/S1516-14392010000100008Microstructural and nonohmic properties of ZnO.Pr6O11 CoO polycrystalline systemMiguel Angel RamírezJosé Francisco FernándezJosé de FrutosPaulo Roberto BuenoElson LongoJosé Arana VarelaThe microstructure and electrical properties of varistors composed of (95-x) ZnO + x Pr6O11 + 5 CoO (ZPC), (x = 0.1, 0.5 and 1.0) and sintered at 1300 and 1350 °C, were investigated. According to X-ray diffraction, several phases (ZnO, Pr2O3 and Pr2CoO4) are present when x = 1.0. Using Scanning Electron Microscopy, all of these compositions contain precipitates. These phases are important regarding the development of the microstructure and the electrical properties. The samples with x = 0.1 introduce the best nonohmic behavior (α = 9.0), however when x = 0.5 the electrical properties are highly degraded due to the small quantity of effective barriers. The density of superficial states N IS and donor concentration Nd decreases with Pr6O11 addition. The decrease in the donor concentration is attributed to the annihilation of the donor defects according to the transformation of praseodymium oxides from Pr6O11 to Pr2O3.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392010000100008electrical propertiesvaristorsgrain boundarymicrostructure |
| spellingShingle | Miguel Angel Ramírez José Francisco Fernández José de Frutos Paulo Roberto Bueno Elson Longo José Arana Varela Microstructural and nonohmic properties of ZnO.Pr6O11 CoO polycrystalline system Materials Research electrical properties varistors grain boundary microstructure |
| title | Microstructural and nonohmic properties of ZnO.Pr6O11 CoO polycrystalline system |
| title_full | Microstructural and nonohmic properties of ZnO.Pr6O11 CoO polycrystalline system |
| title_fullStr | Microstructural and nonohmic properties of ZnO.Pr6O11 CoO polycrystalline system |
| title_full_unstemmed | Microstructural and nonohmic properties of ZnO.Pr6O11 CoO polycrystalline system |
| title_short | Microstructural and nonohmic properties of ZnO.Pr6O11 CoO polycrystalline system |
| title_sort | microstructural and nonohmic properties of zno pr6o11 coo polycrystalline system |
| topic | electrical properties varistors grain boundary microstructure |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392010000100008 |
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