Researchers at the Carnegie Institution have discovered a new efficient way to pump heat using crystals. The crystals can pump or extract heat, even on the nanoscale, so they could be used on computer chips to prevent overheating or even meltdown, which is currently a major limit to higher computer speeds. The research is published in the Physical Review Letters.
Ronald Cohen, staff scientist at Carnegie's Geophysical Laboratory and Maimon Rose, originally a high school intern now at the University of Chicago carried out the research. They performed simulations on ferroelectric crystals—materials that have electrical polarization in the absence of an electric field. The electrical polarization can be reversed by applying an external electrical field. The scientists found that the introduction of an electric field causes a giant temperature change in the material, dubbed the electrocaloric effect, far above a temperature to a so-called paraelectric state.
"The electrocaloric effect pumps heat through changing temperature by way of an applied electric field," explained Cohen. "The effect has been known since the 1930s, but has not been exploited because people were using materials with high transition temperatures. We found that the effect is larger if the ambient temperature is well above the transition temperature, so low transition temperature materials are preferred."
Ferroelectrics become paraelectric—that is, have no polarization under zero electric field above their transition temperature, which is the temperature at which a material changes its state from ferroelectric to paraelectric.
Rose and Cohen used atomic-scale molecular dynamics simulations, where they followed the behavior of atoms in the ferroelectric lithium niobate as functions of temperature and an electrical field. Maimon Rose started this work as a high school summer intern and is now in his second year as an undergraduate in biology at the University of Chicago. He worked on the project during breaks as an intern supported by EFree, DOE Energy Frontier Research Center at the Geophysical Laboratory. Rose remarked, "Lithium niobate had not been studied before like this. We were pretty surprised to see such a huge temperature change."
Carnegie Institution: http://www.ciw.edu
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
The magnitude-6.0 quake that hit California's Napa Valley wasn't the "big one", but it loaded stress on to the Hayward fault close to the Bay Area
NASA explains what the Curiosity rover photographed on Mars after UFO blog raises questions
Bardarbunga, a subglacial stratovolcano, showing increased seismic activity; 2010 eruption caused air travel chaos
A coffee entrepreneur claims his brew is different — and better — than the trendy civet poop coffee. And it starts with the idea that elephants, unlike humans or civets, are herbivores.
Structural colours are more visible and vivid than those that use pigments as many examples from the natural world demonstrate. But sometimes pure white is what is required
Dutch biologist Ingrid van der Meer often meets with disbelief when she talks about her work on dandelions and how it could secure the future of road transport.
Pretend for a minute that it’s 1875 and you’re a mining engineer whose job it is to figure out how much gold is in them thar hills. Get it wrong, and your company is going to waste a lot of time and money hunting for gold that’s not there—or worse yet, miss out on the mother lode
It can only switch from black to transparent and back again, but that's a start
What happens when you add folds to materials that are only a few atoms thick? Several scientists set out to find the answer — and discovered that these nano-wrinkles can be quite useful.
A battery tattoo powered by perspiration has been unveiled by chemists in California.