Micromagnetic studies of magnetite films using μ -Hall sensor arrays

The local-field distribution on magnetite films fabricated on MgO and MgAl₂O₄ substrates was measured with a μ-Hall sensor array. The stray-field hysteresis loops observed here mainly consist of a hysteretic contribution and superimposed field spikes near the coercive field. From an analysis of these Hall data, magnetization and magnetic force microscopy measurements as well as micromagnetic simulations it is concluded that the local field arises from (i) magnetic domain tilt, (ii) out-of-plane domains due to a broad easy axis distribution, and (iii) stray fields emanating from domain walls.