Magnetic Properties of Fe3O4 antidots arrays synthesized by atomic layer deposition and focused ion beam lithography

Magnetic films of magnetite (Fe3O4) with controlled defects, usually called antidots arrays, where synthesized by a new technique called AFIR (Artificial Force Induced Reaction), that considers the deposition of a thin film by atomic layer deposition, the generation of holes using focused ion beam milling in the case of squared and hexagonal lattices, and the subsequent thermal reduction process of antidots arrays. Magnetic characterizations were carried out by magneto optic Kerr effect, showing the enhancement of the coercivity for the antidots arrays. The presence of the ordered non-magnetic holes induces a demagnetization field distribution that change the magnetization switching mechanism, and thermal reduction from Fe2O3 to Fe3O4 produces vacancies (porosity) in the material. Magnetic behavior was studied by mean of micromagnetic simulations, in where was possible to simulate the vacancies in the continuous film and the controlled defects. This technique opens a new route of manufacture ordered antidots arrays of magnetic oxides with variable lattice parameters.