Giant magnetic moment enhancement of nickel nanoparticles embedded in multi-walled carbon nanotubes

Abstract

We report a giant magnetic moment enhancement of ferromagnetic nickel nanoparticles (11 nm) embedded in multi-walled carbon nanotubes. High-energy synchrotron x-ray diffraction experiment and chemical analysis are used to accurately determine the ferromagnetic nickel concentration. Magnetic measurements up to 900 K show an intriguing result-the saturation magnetization of the nickel nanoparticles embedded in the multi-walled carbon nanotubes is about 3.4 times as much as the value expected from the measured nickel concentration while the Curie temperature is the same as that of bulk nickel. The implication of this giant magnetic moment enhancement, whatever its origin, is likely to be far reaching-it opens a new avenue for implementing spin-electronics at the molecular level.