Dynamic cantilever magnetometry of individual Co nanosheets and applicable conditions of uniaxial magnetic anisotropy assumption

Abstract

In this work, we investigated individual Co nanosheets by dynamic cantilever magnetometry. For a disk sample, fitting results give consistent magnetic anisotropy from in-plane and out-of-plane magnetization processes. The derived saturation magnetization value is comparable to the bulk value. However, for a rectangular sample, there is a considerable difference between the derived anisotropy constants from the in-plane and out-of-plane. Moreover, the derived saturation magnetization value is much smaller than the bulk value. We conclude that for samples without rotation symmetry, the uniaxial anisotropy assumption is not applicable and a biaxial or more complex magnetic anisotropy should be taken into account in analyzing dynamic cantilever magnetometry measurements.