Question

3 methods of film deposition in electrodeposition technique of nanoparticles synthesis

Answer 1

• Multilayer thin films consist of alternating layers oftwo different materials. The multilayer structurc typically contains sevcral hundrcd repcats of a bilayer unit cell that is characterized by a spatial repeat length or period of a nanometer or greater.
• Multilayers have been widely studied because their properties differ from those of their bulk constituents owing to the two-dimensional structure of the film, the high density of interfaces, and the possibility of interactions such as magnetic coupling between the layers.
• Multilayers are typically made by sputtering, evaporation, chemical vapor deposition, and other vacuum deposition processes, but they can also be made by electrodeposition. Electrodeposition (also known as electroplating) refers to the deposition of a pure material or alloy from a solution (the electrolyte) by the passage of an electric current, for example the precipitation of a film of copper on the cathode when a current is passed between two electrodes immersed in an acid copper sulfate solution.
• The nature of an electrodeposit is determined by many factors including the electrolyte composition, pH, temperature and agitation, the potential applied between the electrodes, and the current density. The resulting films can be crystalline or amorphous, metallic or nonmetallic.
• Alloys may be deposited from solutions containing ions of each constituent. Electrolytes are usually aqueous, although many materials have been deposited from non-aqueous solutions.
• Electrodeposition is important commercially as a process for making protective or decorative coatings on a wide range of objects.
• However, it has rarely been used to make multilayers or other.