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Schaper, Andreas ; Hou, Haoqing ; Greiner, Andreas ; Schneider, R. ; Phillipp, Fritz:
Copper nanoparticles encapsulated in multi-shell carbon cages.
In: Applied Physics A.
Bd. 78
(2004)
.
- S. 73-77.
ISSN 1432-0630
DOI: https://doi.org/10.1007/s00339-003-2199-0
Abstract
Nanoparticles are attracting increasing interest because of their high potential for a great number of practical applications, such as optical and electronic devices, nanoscale storage, and delivery systems. Using Cu-phthalocyanine as precursor material, we have synthesized multi-shell graphitic carbon nanospheres without and with metal encapsulation, depending on the pyrolysis conditions. The encapsulated elemental copper nanocrystals achieved using that route were of the order of 50 nm in size. The particles were characterized in detail by high-resolution transmission electron microscopy (HRTEM) and by energy filtering microscopy (EFTEM). The concentric graphitic carbon shells of the as-grown particles were clearly discernable. After in situ high-temperature annealing, an increase in the degree of order was observed. Under high-voltage electron irradiation and heating, a melting point reduction of the enclosed nanosized copper of more than 200 K could be detected, as compared to the melting point 1083degreesC of bulk copper. Time-resolved imaging revealed the displacement of the melting copper by migration through the carbon shells, leaving intact carbon cages with a central hole. At intermediate stages of this process the transformation into a hexagonal morphology of the copper nanocrystals was observed.
Weitere Angaben
| Publikationsform: | Artikel in einer Zeitschrift |
|---|---|
| Begutachteter Beitrag: | Ja |
| Keywords: | MAGNETIC-PROPERTIES; ELECTRON-MICROSCOPY; METAL ATOMS; ARC METHOD; PARTICLES; SPHERES; NANOTUBES; CARBIDE; ONIONS; NANOCLUSTERS |
| Institutionen der Universität: | Fakultäten > Fakultät für Biologie, Chemie und Geowissenschaften > Fachgruppe Chemie > Lehrstuhl Makromolekulare Chemie II > Lehrstuhl Makromolekulare Chemie II - Univ.-Prof. Dr. Andreas Greiner Fakultäten Fakultäten > Fakultät für Biologie, Chemie und Geowissenschaften Fakultäten > Fakultät für Biologie, Chemie und Geowissenschaften > Fachgruppe Chemie Fakultäten > Fakultät für Biologie, Chemie und Geowissenschaften > Fachgruppe Chemie > Lehrstuhl Makromolekulare Chemie II |
| Titel an der UBT entstanden: | Nein |
| Themengebiete aus DDC: | 500 Naturwissenschaften und Mathematik > 540 Chemie |
| Eingestellt am: | 14 Apr 2015 08:09 |
| Letzte Änderung: | 06 Nov 2023 13:57 |
| URI: | https://eref.uni-bayreuth.de/id/eprint/9734 |