Effects of Ni Doping on [MnO6] Octahedron in LiMn2O4

作者：Yingjin Wei, Lei Yan, Chen Wang, Xiaoguang Xu, Feng Wu, G. Chen · 发表于：The Journal of Physical Chemistry B · 年份：2004 · DOI：10.1021/jp0479522 · 被引用次数：227 · 研究领域：Advancements in Battery Materials、Multiferroics and related materials、Ferroelectric and Piezoelectric Materials

LiNi x Mn 2 - x O 4 ( x ≤ 0.5) powders were synthesized using a sol−gel technique. It was found that partial Ni atoms occupy the 8a sites in heavy doped LiNi x Mn 2 - x O 4 via X-ray diffraction. XPS results showed an increase and a decrease in the average valence state of Mn and Ni ions, respectively, with the nickel content. Five Raman modes of LiNi x Mn 2 - x O 4 were observed. The A 1g band was observed being shifted to higher frequency for x ≤ 0.2 and shifted to lower frequency for x > 0.2. It was indicated that the most rigid [MnO 6 ] octahedron occurs at x = 0.2. [MnO 6 ] octahedron in LiNi 0.2 Mn 1.8 O 4 possesses the strongest rigidity with respect to the other LiNi x Mn 2 - x O 4 ( x < 0.5 and ≠ 0.2).