New alloys mean all that glitters need not be gold for electronic applications
By Darren Quick
October 14, 2010
Gold has long been seen as a financial safe haven in times of economic uncertainty. This don’t look like changing any time soon with the price of gold reaching a record high of US$1377.60 an ounce this week on the Comex division of the New York Mercantile Exchange. That might be good news for gold miners but not so good for the manufacturers of electronic devices that are reliant on not only gold, but also other precious metals. In some modern day alchemy, researchers have modeled and developed new classes of alloy materials that boast the properties that makes gold so attractive for electronic applications.
The costly noble metals, including gold, platinum, rhodium, palladium and silver, are widely used in electronic applications due to their combination of excellent conductivity paired with resistance to oxidation and corrosion. Looking to find less costly but equally durable and effective alternatives, researchers at the University of Connecticut have developed new classes of materials that behave much like gold and its counterparts when exposed to the oxidizing environments that degrade traditional base metals.
The research team investigated nickel, copper and iron – all inexpensive materials the team felt may offer promise. Using a combination of theoretical analysis to select the appropriate ingredients, and materials engineering at the atomic level, the team was able to create designer materials.
Using inexpensive base metals, the researchers say they were able to synthesize various alloys and achieve higher conductivity native oxide scales through one of three processes: doping to enhance carrier concentration, inducing mixed oxidation states to give electron/polaron hopping, and/or phase separation for conducting pathways.
The University of Connecticut researchers claim their work has demonstrated an improvement in contact resistance of up to one-million-fold over that for pure base metals, so that base metal contacts can now be prepared with contact properties near those of pure gold.
Their research appears online in the October 12th issue of the journal Applied Physics Letters.