使用调制元素反应剂方法合成晶状斯库克特鲁迪特超级网
Joshua R Williams1, Arwyn L E Smalley, Heike Sellinschegg
1Department of Chemistry and Material Science Institute, University of Oregon, Eugene, Oregon 97403, USA.
Journal of the American Chemical Society
|August 21, 2003
概括
研究人员通过化层层的薄膜,创造了新的 skutterudite 超级网. 短重复单位形成了 skutterudites,而长重复周期持续,揭示了新的超级晶格结构.
科学领域:
- 材料科学 材料科学 材料科学
- 固态化学 固态化学
背景情况:
- 斯卡特鲁迪特 (M4Sb12) 是一个有前途的热电材料.
- 超级网格通过分层结构提供可调节的特性.
研究的目的:
- 为了合成和表征有控制成分的 skutterudite 超级格子.
- 为了研究层叠膜在回火后的结构演变.
主要方法:
- 用不同的重复单元准备 (AB) (x) (CD) (y) (z) 样本.
- 进行X射线衍射和反射分析,以监测结构变化.
- 在不同的温度和时间进行回火.
主要成果:
- 无形的分层薄膜转化为晶体的 skutterudite 超级平面.
- 短重复单位相互扩散并形成斯基特鲁迪特 (M = Fe,Co,Ir).
- 长时间的重复周期在化后仍然完好无损,形成了一个持久的超级晶格结构.
- 斯库特鲁迪特石以随机的晶体学定位结晶.
- 在IrSb(3) /CoSb(3) 样本中观察到一种新的超级晶格结构.
结论:
- 成功合成了斯库特鲁迪特超级晶状体,并保持了长周期.
- 展示了一种新的超级格子结构,有可能用于先进材料应用.
相关概念视频
Recrystallization: Solid–Solution Equilibria
Recrystallization is a purification technique used to separate impurities from solid compounds. In this technique, no chemical reactions occur. Instead, it exploits physical properties only, specifically, the solubility differences between the desired compound and impurities, either at a single temperature or at different temperatures, and under other selected conditions. The solid-solution equilibrium (solubility equilibrium) of each component in the solution represents a binary phase...
Crystal Density
The crystal lattice structure of a material allows us to determine how many molecules exist in its unit cell. With this information, alongside the unit-cell parameters - three distance parameters (a, b, c) and three angular parameters (α, β, γ).Density (ρ) = (Z × M) / (a × b × c × NA)where:Z is the number of formula units per unit cellM is the molar mass of the substancea, b, and c are the edge lengths of the unit cellNA is Avogadro’s numberFor a simple cubic lattice, atoms are located only at...
Determination of Crystal Structures
In the late 1800s, the revelation that light extended beyond visible wavelengths led to the discovery of X-rays by Wilhelm Roentgen. Recognized as high-energy electromagnetic radiation with short wavelengths, X-rays prompted exploration into their interaction with crystals. Max von Laue proposed in 1912 that the periodic arrangement of atoms, ions, or molecules in crystals would cause them to diffract X-rays, a hypothesis confirmed through experiments with copper sulfate and zinc sulfide...
Imperfections in Crystal Structure: Stoichiometric Point Defects
Schottky defects arise when some lattice points in a crystal, such as those in NaCl, remain unoccupied, creating lattice vacancies without disturbing the overall electrical neutrality of the crystal. This defect is common in ionic crystals where the positive and negative ions are similar in size, as seen in sodium chloride and cesium chloride. The presence of Schottky defects enables the crystal to conduct electricity to a small extent through an ionic mechanism. Electric fields cause nearby...


