Magnetism of Low-dimensional Metallic Structures

The chapter “Magnetism of low-dimensional metallic structures” reviews experiments on the magnetism of surface-supported low-dimensional structures of 3d metals. Controlling the static and dynamic magnetic behavior of both individual impurities and supported nanostructures on nonmagnetic surfaces represents a fundamental challenge as well as a prerequisite to design magnetic storage and logic devices of novel conception. We describe the governing principles of self-organized growth of metallic nanostructures at surfaces and outline approaches to drive and steer self-assembly processes. The controlled assembly of metal nanostructures on crystalline surfaces combined with scanning probe measurements and synchrotron radiation spectroscopy allows us to track the evolution of the magnetic properties from single atoms to finite-sized particles, atomic chains, and two-dimensional layers, highlighting the significance of size, coordination, and interface effects at the atomic scale. As examples, we report on the giant magnetic anisotropy and unquenched orbital moments observed in nanoparticles, unusual oscillations of the easy axis of magnetization in atomic chains of variable thickness, and metastable ferromagnetic order in one-dimension. We discuss the important role played by interactions with a nonmagnetic substrate and point out approaches to control and tune magnetism in nanoscale structures by taking advantage of coordination and hybridization effects.