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    Studies towards synthesis, evolution and alignment characteristics of dense, millimeter long multiwalled carbon nanotube arrays
    (Frankfurt, M. : Beilstein-Institut zur Förderung der Chemischen Wissenschaften, 2011) Mahanandia, P.; Schneider, J.J.; Engel, M.; Stühn, B.; Subramanyam, S.V.; Nanda, K.K.
    We report the synthesis of aligned arrays of millimeter long carbon nanotubes (CNTs), from benzene and ferrocene as the molecular precursor and catalyst respectively, by a one-step chemical vapor deposition technique. The length of the grown CNTs depends on the reaction temperature and increases from ~85 μm to ~1.4 mm when the synthesis temperature is raised from 650 to 1100°C, while the tube diameter is almost independent of the preparation temperature and is ~80 nm. The parallel arrangement of the CNTs, as well as their tube diameter can be verified spectroscopically by small angle X-ray scattering (SAXS) studies. Based on electron diffraction scattering (EDS) studies of the top and the base of the CNT films, a root growth process can be deduced.
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    Magnetization Dynamics of an Individual Single-Crystalline Fe-Filled Carbon Nanotube
    (Weinheim : Wiley-VCH, 2019) Lenz, Kilian; Narkowicz, Ryszard; Wagner, Kai; Reiche, Christopher F.; Körner, Julia; Schneider, Tobias; Kákay, Attila; Schultheiss, Helmut; Weissker, Uhland; Wolf, Daniel; Suter, Dieter; Büchner, Bernd; Fassbender, Jürgen; Mühl, Thomas; Lindner, Jürgen
    The magnetization dynamics of individual Fe-filled multiwall carbon-nanotubes (FeCNT), grown by chemical vapor deposition, are investigated by microresonator ferromagnetic resonance (FMR) and Brillouin light scattering (BLS) microscopy and corroborated by micromagnetic simulations. Currently, only static magnetometry measurements are available. They suggest that the FeCNTs consist of a single-crystalline Fe nanowire throughout the length. The number and structure of the FMR lines and the abrupt decay of the spin-wave transport seen in BLS indicate, however, that the Fe filling is not a single straight piece along the length. Therefore, a stepwise cutting procedure is applied in order to investigate the evolution of the ferromagnetic resonance lines as a function of the nanowire length. The results show that the FeCNT is indeed not homogeneous along the full length but is built from 300 to 400 nm long single-crystalline segments. These segments consist of magnetically high quality Fe nanowires with almost the bulk values of Fe and with a similar small damping in relation to thin films, promoting FeCNTs as appealing candidates for spin-wave transport in magnonic applications. © 2019 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim