February 2017
Electricity Found to Flow Without the Heat in Novel Material
Vanadium dioxide (VO2) nanobeams show exotic electrical and thermal properties. In this false-color scanning electron microscopy image, thermal conductivity was measured by transporting heat from the suspended heat source pad (red), through the VO2 nanobeam, and to the sensing pad (blue).
Scientific Achievement
Users and staff at the Molecular Foundry discovered that electrons in vanadium dioxide can conduct electricity without conducting heat.
Significance and Impact
The findings could lead to a wide range of applications, such as thermoelectric systems that convert waste heat from engines and appliances into electricity.
Research Details
- For most metals, good conductors of electricity are also good conductors of heat, but not in vanadium dioxide (VO2).
- Computer simulations and X-ray scattering experiments of VO2 determined the proportion of thermal conductivity attributable to the vibration of the material’s crystal lattice, called phonons, and to the movement of electrons.
- VO2’s thermal conductivity attributed to the electrons is ten times smaller than what would be expected.