Size-Dependent Structure Relations between Nanotubes and Encapsulated Nanocrystals
| Autor: | N. A. Kiselev, Andrei A. Volykhov, Andrei A. Eliseev, Jeremy Sloan, Nikolay I. Verbitskiy, N. S. Falaleev, Andrei S. Kumskov, Alexey V. Lukashin, V. G. Zhigalina, Alexander L. Vasiliev, Lada V. Yashina |
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| Rok vydání: | 2017 |
| Předmět: |
Materials science
Mechanical Engineering Bioengineering 02 engineering and technology General Chemistry Carbon nanotube 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences 0104 chemical sciences law.invention Crystal Crystallography Nanocrystal Chemical physics Ab initio quantum chemistry methods Transmission electron microscopy law General Materials Science 0210 nano-technology High-resolution transmission electron microscopy Confined space Stoichiometry |
| Zdroj: | Nano Letters. 17:805-810 |
| ISSN: | 1530-6992 1530-6984 |
| Popis: | The structural organization of compounds in a confined space of nanometer-scale cavities is of fundamental importance for understanding the basic principles for atomic structure design at the nanolevel. Here, we explore size-dependent structure relations between one-dimensional PbTe nanocrystals and carbon nanotube containers in the diameter range of 2.0-1.25 nm using high-resolution transmission electron microscopy and ab initio calculations. Upon decrease of the confining volume, one-dimensional crystals reveal gradual thinning, with the structure being cut from the bulk in either a110or a100growth direction until a certain limit of ∼1.3 nm. This corresponds to the situation when a stoichiometric (uncharged) crystal does not fit into the cavity dimensions. As a result of the in-tube charge compensation, one-dimensional superstructures with nanometer-scale atomic density modulations are formed by a periodic addition of peripheral extra atoms to the main motif. Structural changes in the crystallographic configuration of the composites entail the redistribution of charge density on single-walled carbon nanotube walls and the possible appearance of the electron density wave. The variation of the potential attains 0.4 eV, corresponding to charge density fluctuations of 0.14 e/atom. |
| Databáze: | OpenAIRE |
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