Inferring the magnetic anisotropy of a nanosample through dynamic cantilever magnetometry measurements

Abstract

The magnetic anisotropy of bit-patterned media, such as a mesocrystal, is a key parameter in spintronics. Here, we utilize the high sensitivity of dynamic cantilever magnetometry to investigate the foundation of a mesocrystal, an individual CoFe2O4 pyramid nanocrystal. The magnetic anisotropy of the nanosample can be inferred through quantitatively correlating the main features in the evolution of the magnetic energy with frequency shifts in dynamic cantilever magnetometry measurements. Magnetometry data taken at 280 K exhibit hybrid magnetic anisotropy, including uniaxial anisotropy and cubic anisotropy. Low-temperature measurements further confirm the previously reported single-domain state and indicate that the cubic anisotropy is mainly magnetocrystalline anisotropy, while uniaxial anisotropy is likely to be induced by the interface between the CoFe2O4 pyramid and the BiFeO3 layer. The analysis provides an alternative interpretation for dynamic cantilever magnetometry data, which may extend the application of magnetometry.