In the physical sciences, a multilayer or stratified medium is a stack of different
thin film
A thin film is a layer of material ranging from fractions of a nanometer ( monolayer) to several micrometers in thickness. The controlled synthesis of materials as thin films (a process referred to as deposition) is a fundamental step in many ...
s. Typically, a multilayer is man made for a specific purpose. Since layers are thin with respect to some relevant length scale,
interface
Interface or interfacing may refer to:
Academic journals
* ''Interface'' (journal), by the Electrochemical Society
* '' Interface, Journal of Applied Linguistics'', now merged with ''ITL International Journal of Applied Linguistics''
* '' Int ...
effects are much more important than in bulk materials, giving rise to novel physical properties.
The term "multilayer" is ''not'' an extension of "
monolayer" and "
bilayer
A bilayer is a double layer of closely packed atoms or molecules.
The properties of bilayers are often studied in condensed matter physics, particularly in the context of semiconductor devices, where two distinct materials are united to form jun ...
", which describe a ''single'' layer that is one or two molecules thick. A multilayer medium rather consists of several thin films.
Examples
An
optical coating, as used for instance in a
dielectric mirror, is made of several layers that have different
refractive index
In optics, the refractive index (or refraction index) of an optical medium is a dimensionless number that gives the indication of the light bending ability of that medium.
The refractive index determines how much the path of light is bent, or ...
es.
Giant magnetoresistance
Giant magnetoresistance (GMR) is a quantum mechanical magnetoresistance effect observed in multilayers composed of alternating ferromagnetic and non-magnetic conductive layers. The 2007 Nobel Prize in Physics was awarded to Albert Fert and Peter G ...
is a macroscopic quantum effect observed in alternating ferromagnetic and non-magnetic conductive layers.
See also
*
Transfer-matrix method (optics)
The transfer-matrix method is a method used in optics and acoustics to analyze the propagation of electromagnetic or acoustic waves through a stratified medium. This is for example relevant for the design of anti-reflective coatings and diele ...
*
Dielectric mirror
References
*
Thin films
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