Probing planar arrays of magnetic nano-particles by the extraordinary Hall effect

The extraordinary Hall effect has been used to determine the blocking temperature, magnetocrystalline anisotropy and magnetic moment of far-separated Co nano-particles arranged in single-layer arrays. The total mass of 3 nm diameter Co particles produced by the low energy clusters beam deposition (LECBD) technique corresponded to as little as 0.01 nm thick layers. The results have been confirmed by magnetization measurements of similar but much thicker samples. The technique is shown to be a simple and reliable information source in the limiting cases of diluted planar arrays of magnetic nano-particles.