A drastic breakdown of a textbook law changed everything that we know about conductors of electricity and resulted in finding a metal that conducts electricity without conducting heat.
The metal, found in 2017, contradicts something called the Wiedemann-Franz Law, which basically states that good conductors of electricity will also be proportionally good conductors of heat, which is why things like motors and appliances get so hot when you use them regularly.
Known as metallic vanadium dioxide (VO2), the metal is seemingly capable of conducting electricity without the accompanying heat. VO2 is already well known for its strange ability to switch from a see-through insulator to a conductive metal at a temperature of 67 degrees Celsius (152 degrees Fahrenheit).
The study that led to the revelation about VO2 was carried out by a team of scientists from the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and at the University of California, Berkeley back in January. The researchers were both surprised by and excited to witness this material’s unique capabilities.
To uncover this bizarre property, the team looked at the way that electrons move within vanadium dioxide’s crystal lattice, as well as how much heat was being generated.
Surprisingly, they found that the thermal conductivity that could be attributed to the electrons in the material was 10 times smaller than that amount predicted by the Wiedemann-Franz Law. The reason for this appears to be the synchronised way that the electrons move through the material.
“The electrons were moving in unison with each other, much like a fluid, instead of as individual particles like in normal metals,” said lead researcher Junqiao Wu from Berkeley Lab’s Materials Sciences Division.
How can we use VO2?
Researchers already knew of a handful of other materials that conduct electricity better than heat, but they only display those properties at temperatures hundreds of degrees below zero, which makes them highly impractical for any real-world applications.
Not only does this unexpected property change what we know about conductors, it could also be incredibly useful – the metal could one day be used to convert wasted heat from engines and appliances back into electricity, or even create better window coverings that keep buildings cool.
The team notes that VO2 has the potential to be used to remove, or at least reduce, the heat in engines, or to create a window coating that “improves the efficient use of energy in buildings.” Imagine being able to cool down a room without using any air conditioning or standing fans, or keeping the heat inside of a building during the Winter.
Sources: Science Alert, Futurism
