One-Step Solvent-Free Synthesis and Characterization of Zn1−x Mnx Se@C Nanorods and Nanowires
| Autor: | Aharon Gedanken, Daniel H. Rich, O. Moshe, Ilana Perelshtein, Sayan Bhattacharyya |
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| Rok vydání: | 2008 |
| Předmět: |
Materials science
Nanowire Cathodoluminescence Nanotechnology Condensed Matter Physics Electronic Optical and Magnetic Materials law.invention Biomaterials chemistry.chemical_compound Crystallography symbols.namesake chemistry Amorphous carbon law Electrochemistry symbols Atomic ratio Zinc selenide Nanorod Electron paramagnetic resonance Raman spectroscopy |
| Zdroj: | Advanced Functional Materials. 18:1641-1653 |
| ISSN: | 1616-301X |
| Popis: | The carbon-encapsulated, Mn-doped ZnSe (Zn1−xMnxSe@C) nanowires, nanorods, and nanoparticles are synthesized by the solvent-free, one-step RAPET (reactions under autogenic pressure at elevated temperature) approach. The aspect ratio of the nanowires/nanorods is altered according to the Mn/Zn atomic ratio, with the maximum being observed for Mn/Zn = 1:20. A 10–20 nm amorphous carbon shell is evidenced from electron microscopy analysis. The replacement of Zn by Mn in the Zn1−xMnxSe lattice is confirmed by the hyperfine splitting values in the electron paramagnetic resonance (EPR) experiments. Raman experiments reveal that the Zn1−xMnxSe core is highly crystalline, while the shell consists of disordered graphitic carbon. Variable-temperature cathodoluminescence measurements are performed for all samples and show distinct ZnSe near-band-edge and Mn-related emissions. An intense and broad Mn-related emission at the largest Mn alloy composition of 19.9% is further consistent with an efficient incorporation of Mn within the host ZnSe lattice. The formation of the core/shell nanowires and nanorods in the absence of any template or structure-directing agent is controlled kinetically by the Zn1−xMnxSe nucleus formation and subsequent carbon encapsulation. Mn replaces Zn mainly in the (111) plane and catalyzes the nanowire growth in the [111] direction. |
| Databáze: | OpenAIRE |
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