在a-site-ordered perovskites中的平方坐标mn的各种价值状态
Youwen Long1, Takashi Saito, Masaichiro Mizumaki
1Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan. ywlong@msk.kuicr.kyoto-u.ac.jp
Journal of the American Chemical Society
|October 17, 2009
概括
研究人员合成了A位点排序的矿LaMn3Cr4O12和LaMn3Ti4O12. 他们发现,在A位点的价值可以有所变化,挑战了长期以来认为它仅仅是Mn3+的信念.
科学领域:
- 材料科学 材料科学 材料科学
- 固态化学 固态化学
- 晶体学 晶体学是指结晶学.
背景情况:
- A-site-ordered矿是一种具有独特结构和电子特性的材料类.
- 在这些矿中,正方形坐标的A位点传统上与Jahn-Teller活性Mn3+) 离子有关.
- 了解矿中离子的价值状态对于预测和调整它们的性质至关重要.
研究的目的:
- 为了合成和描述新的A位点排序的矿,特别是LaMn3Cr4O12和LaMn3Ti4O12.
- 为了研究这些合成化合物的离子在A位点的价值状态.
- 重新评估对Jahn-Teller活动和Mn价值在A位点在A位点排序的矿石的既定理解.
主要方法:
- 使用高压和高温合成技术来获得目标矿结构.
- 为了阐明离子配置,进行了化学公式的确定和电荷状态分析.
- 频谱或衍射方法 (隐含的,没有明确说明) 可能用于结构和价值状态分析.
主要成果:
- 合成和表征了LaMn3Cr4O12,揭示了LaMn(3+) ((3) Cr ((3+) ((4) O ((12) 的电荷公式与Mn ((3+) 在A位点.
- 还合成了LaMn3Ti4O12,在A位点表现出低于+2的价值,其拟议的电荷组合是LaMn{1.67+) {3) Ti{4+) {4) O{12).
- 这些发现表明,在A位点的价值可以从+3到大约+1.67不等,这与之前的假设相反.
结论:
- 在研究中,在苛刻的条件下,成功合成了新型A位点排序的矿.
- 这些结果挑战了长期以来的假设,即这些材料中的A位点Mn仅为Mn3+).
- 观察到的可变价值突出了通过组成控制调整A位点排序矿的性能的潜力.
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