Bond-order–bond-length–bond-strength (bond-OLS) correlation mechanism for the shape-and-size dependence of a nanosolid
Bond-order–bond-length–bond-strength (bond-OLS) correlation mechanism for the shape-and-size dependence of a nanosolid
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DOI：
10.1088/0953-8984/14/34/301
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
Chang Q Sun;B K Tay;X T Zeng;S Li-;T P Chen;Ji Zhou;H L Bai;E Y Jiang
中科院分区：
文献类型：
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作者：
Chang Q Sun;B K Tay;X T Zeng;S Li-;T P Chen;Ji Zhou;H L Bai;E Y Jiang
提出了键序-键长-键强度（键- ols）相关机制，以一致地了解纳米固体形状和尺寸依赖性的起源，旨在为设计具有所需功能的纳米材料提供指导。提出了原子在表面的配位数缺陷导致低配位表面原子的剩余键自发松弛；因此，键能上升（绝对值）。键能的增加不仅对表面原子的内聚能（ECoh）有贡献，而且对弛豫区的能量密度也有贡献。ECoh与纳米固体的自组装、相变和热稳定性等热力学性质有关。当纳米固体的表面曲率和表面原子的比例随粒径的变化而变化时，结合能密度的增加导致了系统的哈密顿量和相关性质的变化，如带隙、核能级位移、声子频率和介电体等。bond-OLS前提不涉及任何假设或可自由调节的参数，导致纳米固体的许多突出性质的预测和实验观察之间的一致性。
A bond-order–bond-length–bond-strength (bond-OLS) correlation mechanism is presented for consistent insight into the origin of the shape-and-size dependence of a nanosolid, aiming to provide guidelines for designing nanomaterials with desired functions. It is proposed that the coordination number imperfection of an atom at a surface causes the remaining bonds of the lower-coordinated surface atom to relax spontaneously; as such, the bond energy rises (in absolute value). The bond energy rise contributes not only to the cohesive energy (ECoh) of the surface atom but also to the energy density in the relaxed region. ECoh relates to thermodynamic properties such as self-assembly, phase transition and thermal stability of a nanosolid. The binding energy density rise is responsible for the changes of the system Hamiltonian and related properties, such as the bandgap, core-level shift, phonon frequency and the dielectrics of a nanosolid of which the surface curvature and the portion of surface atoms vary with particle size. The bond-OLS premise, involving no assumptions or freely adjustable parameters, has led to consistency between predictions and experimental observations of a number of outstanding properties of nanosolids.