Magnetism in Gold nanoparticle: Formation of large orbital moment at the interface

In this letter, we have tried to find out the origin of magnetism in Gold nanoparticles (Au-NPs). We observe that upon incorporating Gold nanoparticles (Au-NPs) in Fe3O4 nanoparticle medium the net magnetisation increases compared to the pure Fe3O4 nanoparticle medium. This increase of magnetization can be attributed to the large orbital magnetic moment formation at the Au/magnetic particle interface indicating that magnetism observed in Au-NPs is an interfacial effect.