Magnetic behaviour of hybridmagnetite/organic semiconductor bilayers

We report on the magnetic properties of hybrid bilayers constituted by magnetite (Fe3O4) films, with thicknesses in the range 10–60 nm, grown at room temperature by the pulsed electron deposition method directly on top of an Alq3 organic semiconductor layer. The samples morphology has been thoroughly characterized as a function of the film thickness and a rms roughness of about 10% of the film thickness was estimated. Magnetometric analyses were performed at room temperature for different thicknesses of magnetite films deposited on Alq3. All the analysed stacks are ferromagnetic with in-plane magnetization. Moreover, a coherent trend of the magnetic properties' dependence on layer thickness is demonstrated. Film quality, nano-granular morphology and magnetic properties persist even down to 10 nm, i.e. close to the interface with the organic layer.