A study of electrical properties of zircon ceramics doped with different dopants
| dc.contributor.author | Dahanayake, U. | |
| dc.contributor.author | Karunaratne, B. S. B. | |
| dc.date.accessioned | 2024-09-27T06:16:05Z | |
| dc.date.available | 2024-09-27T06:16:05Z | |
| dc.date.issued | 2001-11-16 | |
| dc.description.abstract | Zircon (ZrSi04) is tetragonal: 141/ amd, Z=4 and the ideal structure consists of chains of alternating, edge-sharing Si04 tetrahedra and ZrOs triangular dodecahedra extending parallel to crystallographic axis c. Zircon is an abundant and inexpensive natural mineral and is mined in very large quantities throughout the world. This material is recognized as a potential ceramic material for the applications at high temperature due to its good combination of many attractive properties such as low thermal expansion, low heat conductivity, good chemical stability, excellent thermal shock resistance and good high temperature properties. Although, many studies on structural properties of zircon ceramics have been reported in literature, electrical properties of zircon has received less attention. It was one of the two reasons why this material was selected for this investigation and the other was the superfluity of zircon in the coastal areas of Sri Lanka. This paper presents the results of a preliminary study on electrical properties of zircon ceramics doped with different dopants. It is expected that the presence of defects in the zircon host structure introduced by doping, could lead to higher electrical conduction. The dopants used in this study were Y103, Fe103, MgO, Ybl03 and EU1O3. The study revealed that the electrical conductivity and the dielectric constant (s.) of doped zircon increased with increasing temperature, irrespective of the dopant. A good conductivity enhancement was observed in 10 mol% Y103 doped zircon and 10 mol% Fe203 doped zircon with the conductivity values 7.74 x 10-5 S em" (Er- 409;105 Hz) and 2.56 x 10-5 S ern" (Er-707; 105 Hz) respectively at 700°C. These conductivity values are about one order of magnitude higher than that of zircon without any dopant (3.83 x 10-6S em"). Since the Y203 doped zircon system showed the highest electrical conductivity, a broad range of Y203 dopant levels were investigated. This revealed that the conductivity increased with the dopant level up to 10 mol%. Further addition ofY203 was not effective to conductivity enhancement probably due to increasing the excess content of Y203 as a second phase. It was observed that the dielectric constant of 10 mol% Fe203 doped and 10 mol% Y203 doped zircon systems, having higher conductivity values, increased rapidly with increasing temperature. In contrast, the other systems having lower conductivity values showed only a slight increment in the dielectric constant with increasing temperature. The microstructures of the sintered ceramics were studied using Scanning Electron Microscopy (SEM)and Energy Dispersive X-ray analysis (EDX). It was evident from subsequent microstructural studies that the additive oxides ~03, MgO and EU203 were not substituted into the host structure of zircon and appeared as a second phase. As a result there was no conductivity enhancement due to doping of these oxides. In the case of Y203 ( y3+) and Fez03 (Fe3) doped samples, the most likely reason for the conductivity enhancement is that v" and Fe3+ ions get substituted into the host structure of zircon creating 02- vacancies to maintain the charge neutrality of the material. | |
| dc.identifier.citation | Proceedings & abstracts of the Annual Research Sessions 2001,University of Peradeniya, Peradeniya, Sri Lanka,pp.137 | |
| dc.identifier.isbn | 955-583-063-0 | |
| dc.identifier.uri | https://ir.lib.pdn.ac.lk/handle/20.500.14444/1156 | |
| dc.language.iso | en_US | |
| dc.publisher | University of Peradeniya, Peradeniya, Sri Lanka | |
| dc.subject | Science | |
| dc.subject | Zircon | |
| dc.subject | Electrical | |
| dc.subject | Ceramics | |
| dc.title | A study of electrical properties of zircon ceramics doped with different dopants | |
| dc.type | Article |