Microstructure and local magnetic induction of segmented and alloyed Pd/Co nanocomposites encapsulated inside vertically aligned multiwalled carbon nanotubes

We have successfully synthesized the Co/Pd magnetic and nonmagnetic multisegment nanowires encapsulated inside multiwalled carbon nanotubes (MWCNTs) by using Co and Pd thin-layers deposited on Si substrate by microwave plasma enhanced chemical vapor deposition. Energy dispersive X-ray spectroscopy revealed that MWCNTs were encapsulated with Co and Pd nanowires, separately, at the tube top and the bottom of Co nanowire, respectively. The face-centered-cubic (fcc) structure of Co nanowires was confirmed by a selected area diffraction pattern. We proposed a fruitful description for the encapsulating mechanisms of both Co and Pd multisegment nanowires. The component of magnetic induction from Co region, not Pd region, was then estimated to be 1.2 ± 0.1 T, based on results of off-axis electron holography, which is lower than the expected saturation magnetization of fcc bulk Co of 1.7 T. We proposed a fruitful description for the mechanisms of reduced magnetic induction from Co nanowires.