Large-scale area of magnetically anisotropic nanoparticle monolayer films deposited by MAPLE

Abstract Magnetically anisotropic nanoparticle monolayer films are of great interest for the development of applications such as high-density data storage, sensors. However, the formation of large-scale magnetically anisotropic monolayer film is a challenging task. Here, we provide a new way to fabricate large-scale area of Fe3O4 nanoparticle monolayer films by vacuum deposition technique (matrix-assisted pulsed laser evaporation, MAPLE). During the deposition process, only interactions between nanoparticles influence nanoparticle self-assembly behaviors. A strong magnetic anisotropy, characterized by in-plane and out-of-plane coercivity and saturation field obtained by DCM (dynamic cantilever magnetometry), was obtained both in cubic and spherical Fe3O4 nanoparticle monolayer films. The inter-particle dipolar interaction but not crystal anisotropy is responsible for this effective magnetic anisotropy, which has been proved by Monte-Carlo simulations.