The World's Smallest Diamonds are Used to Make Wires Just Three Atoms Wide
Diamonds are a girl's best friend. Diamondoids - the tiniest possible cuts of the precious gem - are apparently one of a scientist's best partners. A group of researchers at Stanford University and the Department of Energy's SLAC National Accelerator Laboratory have now created the world's thinnest electrical wires by using these diamondoids, according to a report from Phys Org.
These new wires are a mere three atoms wide, made by assembling and fusing the atoms "LEGO-style".
"What we have shown here is that we can make tiny, conductive wires of the smallest possible size that essentially assemble themselves," lead author Hao Yan, a Stanford postdoctoral researcher, explained. "The process is a simple, one-pot synthesis. You dump the ingredients together and you can get results in half an hour. It's almost as if the diamondoids know where they want to go."
Study co-author Nicholas Melosh added that their method is the first one revealed to create an actual nanowire containing a solid crystalline core with good electronic properties. Melosh is an associate professor at SLAC and Stanford, as well as an investigator with SIMES (Stanford Institute for Materials and Energy Sciences) at SLAC.
The semi-conducting core of the wire is a combination of copper and sulfur that's known as chalcogenide. It's enveloped with a ring of diamondoids that acts as an insulator. Miniscule-sized diamonds are important, Melosh stressed, because it allows the scientists to assemble the materials with utmost precision. A small-scale - in this case, atomic-scale - material can have very different properties than the same material made in bulk or larger.
Diamondoids are attracted to each other very strongly because of what's called van der Waals forces. The team took advantage of this by attaching a sulfur atom to each of the smallest diamondoid and this atom bonded with one copper ion, creating the basic nanowire building block. Due to the van der Waals forces among diamondoids, the building blocks came together and attached to the tip of the nanowire.
"Much like LEGO blocks, they only fit together in certain ways that are determined by their size and shape," Stanford graduate student Hua Li said. "The copper and sulfur atoms of each building block wound up in the middle, forming the conductive core of the wire, and the bulkier diamondoids wound up on the outside, forming the insulating shell."
The researchers published their findings in Nature Materials.