title: Structural and magnetic characterization of batch-fabricated nickel encapsulated multi-walled carbon nanotubes.
abstract: We report on the growth and fabrication of Ni-filled multi-walled carbon nanotubes (Ni-MWNTs) with an average diameter of 115 nm and variable length of 400 nm-1 µm. The Ni-MWNTs were grown using template-assisted electrodeposition and low pressure chemical vapor deposition (LPCVD) techniques. Anodized alumina oxide (AAO) templates were fabricated on Si using a current controlled process. This was followed by the electrodeposition of Ni nanowires (NWs) using galvanostatic pulsed current (PC) electrodeposition. Ni NWs served as the catalyst to grow Ni-MWNTs in an atmosphere of H2/C2H2 at a temperature of 700 °C. Time dependent depositions were carried out to understand the diffusion and growth mechanism of Ni-MWNTs. Characterization was carried out using scanning electron microscopy (SEM), focused ion beam (FIB) milling, transmission electron microscopy (TEM), Raman spectroscopy and energy dispersive x-ray spectroscopy (EDX). TEM analysis revealed that the Ni nanowires possess a fcc structure. To understand the effects of the electrodeposition parameters, and also the effects of the high temperatures encountered during MWNT growth on the magnetic properties of the Ni-MWNTs, vibrating sample magnetometer (VSM) measurements were performed. The template-based fabrication method is repeatable, efficient, enables batch fabrication and provides good control on the dimensions of the Ni-MWNTs.
authors: Institute of Robotics and Intelligent Systems, ETH Zürich, CH-8092, Switzerland.
authors: M A
authors: MA
authors: Zeeshan
authors: K
authors: K
authors: Shou
authors: S
authors: S
authors: Pané
authors: E
authors: E
authors: Pellicer
authors: J
authors: J
authors: Sort
authors: K M
authors: KM
authors: Sivaraman
authors: M D
authors: MD
authors: Baró
authors: B J
authors: BJ
authors: Nelson