| Al、Co和Mn掺杂对LiNiO2结构的影响 | |
| Structural Changes Induced by Doping in LiNiO2 | |
| 摘要: 本文采用XRD和EXAFS研究Al、Co和Mn原子掺杂对LiNiO2材料结构的影响。XRD结果表明掺杂材料具有与LiNiO2相同的晶体结构，都属于R3m点群，但是晶胞略微缩小，LiNiO2的层状结构得到改善,阳离子有序度增强。从EXAFS数据拟合结果可以看出，引入掺杂原子Al、Co和Mn减弱了Jahn-Teller畸变，使得NiO6八面对称性提高。掺杂Al和Co使得第一壳层Ni-O配位键长减小，掺杂Mn原子影响不明显。Al、Co和Mn掺杂使第二壳层Ni-Ni配位键长减小，Co和Mn掺杂使得第二壳层局域有序度提高，而Al的引入使得第二壳层局域有序度降低。 | |
| 关键词: LiNiO2 EXAFS 掺杂 局域结构 | |
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| Abstract: Structural modifications in LiNiO2 induced by doping of Al, Co and Mn were investigated by XRD and EXAFS. Diffraction experiments show that doping does not modify the phase as LiNiO2, and all structures belong to the R3m group, however, doping of Al, Co and Mn, decreases the size of the unit cell, and limits the cation mixing in lithium layers. From EXAFS data fitting one may see that doping of Al, Co and Mn decreases the Debye-Waller factor of the first shell of Ni-O and weakens the John-Teller distortion of the Ni(Ⅲ)O6 octahedron. Doping by Al and Co in LiNiO2 also decreases the Ni-O bond length while the effect on bond length is not obrious with Mn doping. All dopings decrease also the second shell Ni-Ni bond length. Moreover, doping of Co and Mn decreases the Debye-Waller factor of the second shell increasing the ordering of the Ni-Ni shell, while Al doping increases the Debye-Waller factor and slightly enhances the disorder degree of the Ni-Ni shell. | |
| Keywords: LiNiO2 EXAFS doping local structure | |
| 摘要点击次数: 1233 | |
| 全文下载次数: 1921 | |
| 刘欣艳,赵煜娟,李燕,夏定国,储旺盛,李树军,吴自玉.Al、Co和Mn掺杂对LiNiO2结构的影响[J].无机化学学报,2006,22(6):1007-1012. | |
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