ION BEAM SYNTHESIS AND TAILORING OF NANOSTRUCTURES

Abstract

The basic electronic structure properties of materials are all related to some characteristic lengths whose scales depend on which property is considered. Examples are the Fermi wavelength or the electron mean free path for conductivity, the Debye wavelength for phonons, the dipolar interaction distance for electromagnetic interactions, the pair correlation length for superconductivity, etc., all of which vary typically from ~ 0.1 to several tens of nanometers. A fundamental question in nanoscience is what happens when the physical size of the sample shrinks down to the characteristic length scale of one or another of its basic physical properties? The sample’s electrical, optical, magnetic or mechanical properties will then be radically affected by its size and shape, by the symmetry of its environment, and by its coupling (chemical bonds, radiation, etc.) to the latter. Their hybrid “betwixt atom and bulk” matter nature often directly reflects their electrical, optical or mechanical properties. As we know, the quantum properties are extremely sensitive to the boundary conditions of wave functions in the nano-objects. Hence, not only do such studies require small samples, but in order to be meaningful, they require samples such as nanoclusters or ultrathin films and multilayers with well-controlled shapes, sizes, and interfaces.