八面体c-In2O3纳米晶体的超级晶体结构
Weigang Lu1, Qingsheng Liu, Zhaoyong Sun
1Department of Chemistry and AMRI, University of New Orleans, New Orleans, Louisiana 70148, USA.
Journal of the American Chemical Society
|May 9, 2008
概括
研究人员探索了立方相氧化物 (In2O3) 纳米晶体的三维自我组装到超级晶圆. 这些八面体纳米晶超级晶格表现出单晶状的特征,并为先进的应用提供了新的途径.
科学领域:
- 材料科学 材料科学 材料科学
- 纳米技术纳米技术
- 晶体学 晶体学是指结晶学.
背景情况:
- 纳米晶体超级网的三维自组装正在引起人们的兴趣.
- 通常,球形纳米晶体被用作超级格子的构建块.
- 最近的进展表明使用立方纳米晶体创建超级格子的可行性.
研究的目的:
- 分析和描述两维和三维组件的均立方相氧化 (In2O3) 纳米晶体与八面体形状.
- 报告这些超级晶体 (超级格子) 的观测结果作为一个模型系统.
- 为了在这些超级格子中识别包装结构.
主要方法:
- 使用电子显微镜的观测结果.
- 对二维和三维组件的分析.
- 纳米晶体超级的表征.
主要成果:
- 由八面体In2O3纳米晶体组成的超级晶体/超级网的演示.
- 观察到的超级格子尺度高达几十微米.
- 识别单晶形状的特征,包括楼梯,露台,曲折和空白.
- 发现了三种类型的精确定义的八面体纳米晶包装结构.
结论:
- 对八面体超级晶体系统的研究提供了一个新的研究方向.
- 构建块的形状变化可以扩大超级网格研究.
- 潜在的新概念和应用,如软X射线光子学.
相关概念视频
Ionic Crystal Structures
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Metallic Solids
Metallic solids such as crystals of copper, aluminum, and iron are formed by metal atoms. The structure of metallic crystals is often described as a uniform distribution of atomic nuclei within a “sea” of delocalized electrons. The atoms within such a metallic solid are held together by a unique force known as metallic bonding that gives rise to many useful and varied bulk properties.
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability. Many...
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability. Many...
Crystal Field Theory - Tetrahedral and Square Planar Complexes
Tetrahedral Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Crystal Field Theory - Octahedral Complexes
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
Unit Cells
A crystal's internal structure is an orderly array of atoms, ions, or molecules, and the details of this array significantly influence the solid's properties. In a crystal, periodically repeating 'structural motifs' - which could be atoms, molecules, or groups thereof - create a 'space lattice.' This is essentially a three-dimensional, infinite array of points, each surrounded by its neighbors in an identical way, forming the basic structure of the crystal.A 'unit cell' is a theoretical...
Lattice Centering and Coordination Number
The structure of a crystalline solid, whether a metal or not, is best described by considering its simplest repeating unit, which is referred to as its unit cell. The unit cell consists of lattice points that represent the locations of atoms or ions. The entire structure then consists of this unit cell repeating in three dimensions. The three different types of unit cells present in the cubic lattice are illustrated in Figure 1.
Types of Unit Cells
Imagine taking a large number of identical...
Types of Unit Cells
Imagine taking a large number of identical...


