A group of scientists with the University of Chicago have discovered a way to create a material in which the molecular fragments are jumbled and disordered, but can still conduct electricity extremely well. This goes against all of the rules we know about for conductivity. Credit: Illustration by Frank Wegloski
Key Points:
- Researchers have discovered a way to create a material that can be made like a plastic, but conducts electricity like a metal.
- The work is based on nickel atoms and molecular beads made of carbon and sulfur.
- The breakthrough could point the way to a new class of materials for electronics and similar devices.
Scientists with the University of Chicago have discovered a way to create a material that can be made like a plastic, but conducts electricity more like a metal.
Conductive materials are essential when making any kind of electronic device. Most often, metals like copper, gold and aluminum are used. Then, about 50 years ago, scientists were able to create conductors made out of organic materials. Fundamentally, both types of metallic conductors share a characteristic thought to be essential: they are made up of straight, closely packed rows of atoms or molecules. This means that electrons can easily flow through the material. In fact, scientists thought a material had to have these straight, orderly rows in order to conduct electricity efficiently.
But then, researcher Jiaze Xie, first author on a new paper on the topic, began experimenting with differ material. He strung nickel atoms like pearls into a string of molecular beads made of carbon and sulfur, and began testing. Surprisngly, the material easily and strongly conducted electricity. What’s more, it was incredibly stable.
“We heated it, chilled it, exposed it to air and humidity, and even dripped acid and base on it, and nothing happened,” said Xie.
The most striking aspect, however, was that the molecular structure of the material was disordered.
“From a fundamental picture, that should not be able to be a metal. There isn’t a solid theory to explain this,” said John Anderson, associate professor of chemistry at the University of Chicago and senior author of the study.
After tests, simulations, and theoretical work, the researchers think the material forms layers. Even if the sheets rotate sideways, no longer forming a neat stack, electrons can still move horizontally or vertically—as long as the pieces touch. The end result is unprecedented for a conductive material.
One of the material’s attractive characteristics is new options for processing. For example, metals usually have to be melted in order to be made into the right shape for a chip or device, which limits what you can make with them, since other components of the device have to be able to withstand the heat needed to process these materials. The new material has no such restriction.
Information provided by University of Chicago.