Magnetic Properties of Organic Coated Gold Surfaces

We review here our recent results of experimental observation of room temperature magnetism in gold nanoparticles (NPs) and thin films. Capping gold surfaces with certain organic molecules leads to the appearance of magnetism at room temperature. The surface bonds between the organic molecules and Au atoms give rise to magnetic moments. These magnetic moments are blocked along the bond direction showing huge anisotropy. In the case of atomically flat surfaces, the magnetic moments are giants. An explanation of this orbital ferromagnetism is given. These results point out the possibility to observe magnetism at nanoscale in materials without typical magnetic atoms (transition metals and rare earths), and are of fundamental value to understand the magnetic properties of surfaces.