Abstract:In this study, abnormal hard-magnetic domains were discovered in Fe3O4@C composite material, in which well-ordered 16-nm-sized Fe3O4 cubes were tightly embedded into carbon sheets of tens of nanometers thick. It was found that ca. 40 columns of Fe3O4 nanocubes magnetically self-assembled into a single strip-type domain with perpendicular magnetic anisotropy. More strikingly, remarkable domain misalignments, which were very similar to common edge dislocations among atomic planes in crystal lattices, were clearly observed and termed as "domain dislocation" in this work. The hard-magnetic properties of Fe3O4@C material, including large coercivity of 2150 Oe, high M-R/M-S value of 0.9, and strong anisotropy energy of 3.772 x 10(5) erg/cm(3), were further ascertained by carefully designed electromagnetic absorption contrast experiments. It is anticipated that the discovery of hard-magnetic domains and domain dislocations within 2-D arrays of soft-magnetic nanomaterials will shed new light on the development of high-density perpendicular magnetic recording industry. (C) 2015 AIP Publishing LLC.

Volume:118

Issue:7

Translation or Not:no