There’s a known rule-breaker among materials, and a new discovery by an international team of scientists adds more evidence to back up the metal’s nonconformist reputation. According to a new study led by scientists at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and at the University of California, Berkeley, electrons in vanadium dioxide can conduct electricity without conducting heat.
The findings, to be published in the Jan. 27 issue of the journal Science, could lead to a wide range of applications, such as thermoelectric systems that convert waste heat from engines and appliances into electricity.
For most metals, the relationship between electrical and thermal conductivity is governed by the Wiedemann-Franz Law. Simply put, the law states that good conductors of electricity are also good conductors of heat. That is not the case for metallic vanadium dioxide, a material already noted for its unusual ability to switch from an insulator to a metal when it reaches a balmy 67 degrees Celsius, or 152 degrees Fahrenheit.