Achieving a high cutting-off frequency in the oriented CoFe2O4 nanocubes

Abstract

An effective way for the improvement of resonance frequency was demonstrated by the orientation of CoFe2O4 nanocubes (NCs) after applying a magnetic field. The magnetic holography image of the oriented CoFe2O4 NC arrays was obtained, and the vortex domain structure was found in single CoFe2O4 NCs, which greatly depends on dipolar interactions. Moreover, the cutting-off frequency of oriented CoFe2O4 NCs of 8.8 GHz is achieved with a slight increase in permeability at an extremely low mass fraction (about 10%). This work provides an effective way for optimizing the high-frequency properties of magnetic nanomaterials above GHz.