在NaSbO3中的多态性:在金属氧化物中的结构和结合
Hiroshi Mizoguchi1, Patrick M Woodward, Song-Ho Byeon
1Department of Chemistry, Ohio State University, Columbus, Ohio 43210-1185, USA.
Journal of the American Chemical Society
|March 12, 2004
概括
在高压下合成了一种具有矿结构的新型抗原 (NaSbO(3)) 多态. 这一发现揭示了三元抗化合物中复杂的结合和结构偏好.
科学领域:
- 固态化学 固态化学
- 材料科学是一种材料科学.
- 晶体学 晶体学是指结晶学.
背景情况:
- 三级矿在材料科学中至关重要,但它们的结构多样性和压力下的稳定性尚未完全理解.
- 已知抗蒙酸 (NaSbO(3) 在环境条件下存在于一个ilmenite多态体中.
研究的目的:
- 合成和表征一种新的NaSbO高压多态体.
- 研究这种新型材料的结构,电子和粘合性能.
- 了解不同NaSbO(3) 多态的稳定性的因素.
主要方法:
- 使用单轴分裂球形形压力机 (USSA-2000) 在10.5 GPa和1150°C的高压合成.
- 用X射线衍射来确定晶体结构.
- 光学测量以确定带间隙.
主要成果:
- 一种新型的NaSbO(3) 的矿多态形态被成功合成并恢复到环境条件下.
- 该结构 (空间组 Pnma) 呈现出显著的八面体倾斜扭曲,比离子半径预测的要大.
- 该化合物是一个白色绝缘体,光带间隙为3.4 eV,代表第一个三元矿与Sb ((5+) 在八面体位点.
结论:
- 观察到的扭曲归因于对氧的二次恩-泰勒效应,由强大的Sb-O共价键驱动.
- 在环境条件下,Sb-O共价键和Na-O排斥相互作用之间的冲突使矿结构不稳定,有利于矿多态.
- 对结合的分析解释了ASbO(3) 和ABiO(3) 化合物中违反保林规则的结构的普遍性.
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