Article ID Journal Published Year Pages File Type
5438830 Ceramics International 2017 4 Pages PDF
Abstract
This study investigated the effects of sintering temperature and cooling rates on the positive temperature coefficient of resistance (PTCR) effect and microstructures of Ba1.022-xSmxTiO3 (BST) ceramics sintered at 1200 °C−1260 °C for 30 min in a reducing atmosphere and reoxidized at 700 °C−900 °C for 1 h. The sintering temperature and cooling rates influenced the PTCR effect and microstructure of the BST samples. The resistivity of the samples at room temperature initially decreased and then increased with the increase in the content of Sm2O3. A high sintering temperature resulted in low resistivity of the BST ceramics. Meanwhile, the resistivity of the specimens at room temperature increased with the increase in cooling rates. Furthermore, a rapid cooling rate exerted a significant PTCR effect. The samples exhibited a resistance jump greater than 3.0 orders of magnitude and a low room-temperature resistivity. The behaviour of the microstructure of the as-fired BST ceramics cooled at different rates was also investigated.
Related Topics
Physical Sciences and Engineering Materials Science Ceramics and Composites
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