Rattling ions limit heat flow in materials used to reduce carbon emissions, study finds

Aug 25, 2013

A new study published today in the journal Nature Materialss has found a way to suppress the thermal conductivity in sodium cobaltate so that it can be used to harvest waste energy.

Led by scientists at Royal Holloway University, the team conducted a series of experiments on crystals of sodium cobaltate grown in the University's Department of Physics. X-ray and neutron scattering experiments were carried out at the European Synchrotron Radiation Facility and in the Institut Laue-Langevin in Grenoble, using the UK's national supercomputer facility HECToR to make their calculations.

They believe their approach can easily be applied to other substances, since they only require tiny crystals and will, therefore, guide the design of the next generation of thermoelectric materials.

"The global target to reduce has brought research into thermoelectric materials centre stage," said Professor Jon Goff from the Department of Physics at Royal Holloway.

"If we can design better , we will be able to reduce the of cars by converting waste heat in exhausts into electrical power, as well as cooling hot spots on using solid state refrigerators."

Thermoelectric coolers are also used in air conditioners and in scientific equipment where a rapid response to changes in temperature is required. Energy harvesting is also important in miniaturised electronic devices, including "systems on a chip", and power recovery using this method is useful for any off-grid electricity applications, including in space.

"The development of thermoelectric oxides offers an environmentally clean alternative to current materials that contain elements that are harmful, such as lead, bismuth or antimony, or those that are in limited supply, such as tellurium," added Professor Goff.

Explore further: Exotic alloys for potential energy applications

More information: Suppression of thermal conductivity by rattling modes in thermoelectric sodium cobaltate, DOI: 10.1038/nmat3739

Related Stories

Exotic alloys for potential energy applications

Jun 27, 2013

The search for thermoelectrics, exotic materials that convert heat directly into electricity, has received a boost from researchers at the California Institute of Technology and the University of Tokyo, who have found the ...

Scientists make nontoxic, bendable nanosheets

Apr 11, 2012

(Phys.org) -- Cornell materials scientists have developed an inexpensive, environmentally friendly way of synthesizing oxide crystal sheets, just nanometers thick, which have useful properties for electronics ...

Recommended for you

A greener source of polyester—cork trees

Apr 16, 2014

On the scale of earth-friendly materials, you'd be hard pressed to find two that are farther apart than polyester (not at all) and cork (very). In an unexpected twist, however, scientists are figuring out ...

User comments : 0

More news stories

Impact glass stores biodata for millions of years

(Phys.org) —Bits of plant life encapsulated in molten glass by asteroid and comet impacts millions of years ago give geologists information about climate and life forms on the ancient Earth. Scientists ...