Effect of A-site cationic radius on polycrystalline ceramics La x Sm0.67−x Sr0.33MnO3 prepared by sol–gel technique
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- 作者：Xiaohui Chen ; Qingming Chen ; Fei Jin…
- 关键词：Polycrystalline ceramics ; Sol–gel technique ; Electrical property ; LaxSm0.67−xSr0.33MnO3 perovskite manganite
- 刊名：Journal of Sol-Gel Science and Technology
- 出版年：2016
- 出版时间：November 2016
- 年：2016
- 卷：80
- 期：2
- 页码：474-479
- 全文大小：1,220 KB
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Chemistry
Ceramics,Glass,Composites,Natural Materials
Inorganic Chemistry
Optical and Electronic Materials
Nanotechnology - 出版者：Springer Netherlands
- ISSN：1573-4846
- 卷排序：80
文摘
In this paper, polycrystalline ceramics LaxSm0.67−xSr0.33MnO3 (x = 0.00, 0.10, 0.20, 0.25, 0.30, 0.365, and 0.40) were prepared by sol–gel technique. The structure was tested by X-ray diffraction, which shows that all samples are single phase, but the progressive substitution of Sm3+ by La3+ enlarges the volume of the unit cell. The surface morphology was investigated by scanning electron microscope, which indicates that the samples with better crystallization have higher density. The electrical property was measured by the standard four-probe method, which demonstrates that the resistivity decreases and the metal–insulator transition temperature shifts to higher temperature with increasing La content. Furthermore, the progressive substitution of Sm3+ by La3+ broadens the metal–insulator transition and reduces the temperature coefficient of resistivity. A mechanism based on double exchange is proposed to interpret the results above.