Thin films and interfaces

The definition of a "thin film" is certainly ambiguous. However in current scientific discussion "thin" refers to nanometer-sized length scales. Films with thicknesses of this order of magnitude are extremely important. In biology, examples include membranes and cell walls. In chemistry, examples include surfactants and catalysts. In physics there is a great deal of interest in low-dimensional magnetism and confinement effects. In addition, films and multilayers of these thicknesses are extensively used for information technology.

In all these scientific fields, it is important to determine what occurs at the interfaces on the properties of the film, and the influence of having a severe spatial constraint on the physical properties of the film. A thin film of a material is highly unlikely to have the same properties of the same material in bulk, and the morphology of an interface can significantly change any interactions that can occur between two materials. Films can also be stacked to produce stratified layers, giving global properties to the material that are very different to the properties of the individual constituents.