Berlin 2008 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 29: New materials

HL 29.4: Talk

Tuesday, February 26, 2008, 12:45–13:00, ER 164

Beaded carbon nanofilament via chemical vapor deposition — •Li Song¹, Alexander W. Holleitner², Huihong Qian³, Achim Hartschuh³, Eva M. Weig¹, and Jörg P. Kotthaus¹ — ¹CeNS und Fakultät für Physik, Ludwig-Maximilians-Universität, 80539 München — ²Walter Schottky Institut, Technische Universität München, 85748 München — ³Department für Chemie, Physikalische Chemie, Butenandtstr. 5-13, 81377 München

Due to their low density and extraordinary mechanical properties, carbon filaments and fibers have large commercial applications as reinforcements in composite materials. In order to transfer the maximum load onto the filaments, the interfacial strength between the host matrices and the filaments should be as high as possible. The interfacial strength mostly depends on the surfaces and shapes of the reinforcing filaments. Here, we present a chemical vapor deposition method to synthesize carbon nanofilaments with carbon beads on their surface. The stems of the nanofilaments typically show an average diameter of about 60 nm, while the diameter of the beads is in the range of 200-400 nm. By SEM and AFM analysis we find a necklace-like structure of the carbon nanofilaments. Raman spectra reveal that the beads are made of graphite, while the stems are multi-walled carbon nanotubes admixed with graphite and carbon fibers. The beaded carbon nanofilaments may have applications as reinforcing agents because the mechanical interlocking between beads can produce stronger interfacial adhesion.