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Researchers working at the Ames Laboratory have developed a sputtering technique to readily synthesize silver alloy film architectures in which the nanostructure can be readily designed over a single substrate in order to tailor the mechanical properties of the film.

A continuous silver film on a six inch substrate has been deposited, allowing for structures and properties to be tailored to the substrate in a single deposition run.

Nanotwinned (nt) metals exhibit high strengths, but unlike their nanocrystalline counterparts, nt metals can also exhibit large uniform tensile ductility. Strength and ductility in nt metals are both strongly dependent on the structure.  Ames Laboratory researchers have recently developed a sputtering technique that enables the synthesis of films made of nt silver alloys in which the processing conditions can be used to control the nanostructure architecture; designing specific structures, the plasticity mechanisms that also control the bulk mechanical response can also be varied. As a consequence, films with thicknesses ranging from nanometer to greater than hundreds of microns that combine very high tensile strengths (> 500 MPa) with excellent electrical conductivities that are comparable to pure, coarse grained silver.  This technology may have utility for commercial applications in electronics—for example in the interconnects for flexible displays, where high strength is needed to prevent premature due to repeated mechanical loading along with high conductivity.

• Enables creation of silver alloy films of varying thickness that have very high strength and high conductivity

• Allows mechanical properties of the film to be tailored

 thin film coatings, electronic displays

Ott, R. T. et al. 2013. Tailoring the mechanical behavior of nanotwinned metals through structural design. Proceedings of Materials Science & Technology Conference, Montreal, Canada