...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Physica, B. Condensed Matter >Structural, thermal and morphological studies of magnesium substituted-lithium manganese oxide spinels
【24h】

Structural, thermal and morphological studies of magnesium substituted-lithium manganese oxide spinels

机译：镁取代锂锰氧化物尖晶石的结构，热学和形貌研究

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Coexistence of two phases having space groups of Fd3m and P4(3)32 in the Mg-doped LiMn2O4 spinet is being reported for the first time in this article. Mg-doped LiMn2O4 powders have been synthesized by sol-gel method using citric acid as a chelating agent. X-ray powder diffraction (XRD) studies show that the crystal structure of LiMgxMn2-xO4 for x < 0.25 is a single-phase cubic spinel, which has space group of Fd3m. The cubic spinel structures having space group of Fd3m and P4(3)32 are found to coexist in the compound for x = 0.25. The structure becomes single-phase cubic spinet with space group P43(3)2 for x>0.25. Field emission scanning electron microscopy (FESEM) shows that particle size of various synthesized powders ranges from 100 to 350nm. Particle size decreases with increase in Mg content. Differential thermal analysis (DTA) and thermogravimetry (TG) studies show an exponential decay relationship between Mg-doping content and the decomposition temperature to form nonstoichiometry (LiMgxMn2-xO4-delta) in air atmosphere. Fourier transform infrared spectroscopy (FTIR) analysis shows increase in the number of vibrational bands with increase in Mg content, which indicates ordering of the ions in the case of ordered spinel structure, and consequent reduction of the space group symmetry from O-h(7) to O-7.
机译：本文首次报道了掺Mg的LiMn2O4尖晶石中具有Fd3m和P4（3）32空间群的两相共存。镁掺杂的LiMn2O4粉体是利用柠檬酸作为螯合剂通过溶胶-凝胶法合成的。 X射线粉末衍射（XRD）研究表明，当x <0.25时，LiMgxMn2-xO4的晶体结构为单相立方尖晶石，其空间群为Fd3m。对于x = 0.25，发现化合物Fd3m和P4（3）32的立方尖晶石结构共存于化合物中。当x> 0.25时，该结构成为空间群为P43（3）2的单相立方锥。场发射扫描电子显微镜（FESEM）表明，各种合成粉末的粒径范围为100至350nm。粒度随着镁含量的增加而减小。差热分析（​​DTA）和热重分析（TG）研究表明，在空气中Mg掺杂含量与分解温度之间的指数衰减关系，从而形成非化学计量比（LiMgxMn2-xO4-delta）。傅里叶变换红外光谱（FTIR）分析显示，随着Mg含量的增加，振动带的数量增加，这表明尖晶石结构有序时离子的有序排列，从而使空间群对称性从Oh（7）降低到O-7。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号