tailieunhanh - Báo cáo hóa học: " Synthesis of High Coercivity Core–Shell Nanorods Based on Nickel and Cobalt and Their Magnetic Properties"

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 of High Coercivity Core–Shell Nanorods Based on Nickel and Cobalt and Their Magnetic Properties | Nanoscale Res Lett 2010 5 164-168 DOI S11671-009-9459-7 NANO EXPRESS Synthesis of High Coercivity Core-Shell Nanorods Based on Nickel and Cobalt and Their Magnetic Properties T. N. Narayanan M. M. Shaijumon P. M. Ajayan M. R. Anantharaman Received 25 July 2009 Accepted 2 October 2009 Published online 21 October 2009 to the authors 2009 Abstract Hybrid magnetic nanostructures with high coercivity have immense application potential in various fields. Nickel Ni electrodeposited inside Cobalt Co nanotubes a new system named Ni @ Co nanorods were fabricated using a two-step potentiostatic electrodeposition method. Ni @ Co nanorods were crystalline and they have an average diameter of 150 nm and length of 15 m. The X-ray diffraction studies revealed the existence of two separate phases corresponding to Ni and Co. Ni @ Co nanorods exhibited a very high longitudinal coercivity. The general mobility-assisted growth mechanism proposed for the growth of one-dimensional nanostructures inside nano porous alumina during potentiostatic electrodeposition is found to be valid in this case too. Keywords Magnetic nanowires Nanorods Hybrid nanostructures Core-shell nanostructures Mobility-assisted growth mechanism Introduction Nanostructured materials such as nanowires nanotubes and nanorods are drawing considerable attention of the scientific community because of their tremendous application T. N. Narayanan M. R. Anantharaman El Department of Physics Cochin University of Science Technology Cochin 22 Kerala India e-mail mraiyer@ M. M. Shaijumon P. M. Ajayan Department of Mechanical Engineering Materials Science Rice University Houston TX USA potential in various fields such as solar cells field sensors bioseparation and medical therapy 1 . Designing and controlling the morphology and growth of these nanowire and nanotubes will surely impact the development of nanotechnology 2 3 . The landmark paper on carbon nanotubes by Iijima 4 led to a surge in research activities