tailieunhanh - Báo cáo hóa học: " Synthesis and Characterization of Magnetic Metal-encapsulated Multi-walled Carbon Nanobeads"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Synthesis and Characterization of Magnetic Metal-encapsulated Multi-walled Carbon Nanobeads | Nanoscale Res Lett 2008 3 76-81 DOI s11671-008-9116-6 NANO EXPRESS Synthesis and Characterization of Magnetic Metal-encapsulated Multi-walled Carbon Nanobeads A. Leela Mohana Reddy S. Ramaprabhu Received 28 August 2007 Accepted 9 January 2008 Published online 26 January 2008 to the authors 2008 Abstract A novel cost-effective easy and single-step process for the synthesis of large quantities of magnetic metal-encapsulated multi-walled carbon nanobeads MWNB and multi-walled carbon nanotubes MWNT using catalytic chemical vapour deposition of methane over Mischmetal-based AB3 alloy hydride catalyst is presented. The growth mechanism of metal-encapsulated MWNB and MWNT has been discussed based on the catalytically controlled root-growth mode. These carbon nanostructures have been characterized using scanning electron microscopy SEM transmission electron microscopy TEM and HRTEM energy dispersive analysis of X-ray EDAX and thermogravimetric analysis TGA . Magnetic properties of metal-filled nanobeads have been studied using PAR vibrating sample magnetometer up to a magnetic field of 10 kOe and the results have been compared with those of metal-filled MWNT. Keywords Magnetic metal-filled multi-walled carbon nanobeads MWNB Alloy hydride catalyst Chemical vapour deposition Magnetization Introduction Carbon nanotubes CNTs 1-3 including single-walled and multi-walled carbon nanotubes SWNT and MWNT have attracted tremendous interest both from fundamental and technological perspectives due to their unique physical A. Leela Mohana Reddy S. Ramaprabhu El Department of Physics Alternative Energy Technology Laboratory Indian Institute of Technology Madras Chennai 600036 India e-mail ramp@ and chemical properties 4 . They promise a wide range of practical applications such as catalyst supports in heterogeneous catalysis electronic devices field emitters sensors gas-storage media and molecular wires for nextgeneration electronic devices. Further MWNT filled with .