USF Physicist Finds New Combinations Advance Solid-State Refrigeration

USF News


TAMPA, Fla. (July 8, 2013) - A University of South Florida physicists have proposed  an unconventional solution to a particularly stubborn roadblock in solid-state refrigeration that is considered an  energy-efficient and environmentally-friendly alternative to conventional refrigeration technology.


In current refrigeration technology, the temperature is controlled by a gas that either expands or contracts to manipulate the temperatures. The disadvantage is that the gases used are not environmentally friendly, the process is not energy efficient and the equipment may be bulky.


In solid state refrigeration, scientist apply magnetic, electric or mechanical stress fields to crystalline materials to control temperatures. While such approach could potentially make gas-operated refrigeration obsolete, scientists have struggled to overcome one large hurdle: the amount of temperature drop in solid state refrigeration isn’t dramatic enough to actually cool things down – a few degrees at most.


“This is exactly where our research steps in: to find creative ways to improve the temperature control,” said USF Assistant Professor of Physics Sergey Lisenkov.


In a new article published in the journal Physical Review B, Lisenkov and his colleagues in the Physics Department  propose an unconventional way to enhance efficiency of solid state refrigerants by using multiferroic materials.


In their research, Lisenkov and colleagues  focused on how different caloric effects could coexist in one material.  Caloric effects allow the materials to convert thermal energy into some other type of energy, such as electrical energy, for example.


Lisenkov said researchers wondered if combining two or even more giant caloric effects in one material would produce more desirable temperature drops that would not only have interesting scientific implications but could potentially help  advance solid-state refrigeration technology. The material studied belong to the class of ferroics.


“Surprisingly, we found a very unusual multicaloric effect in one of the most well known “classic" ferroelectric,’” Lisenkov said.


Using computational experiments,  the researchers predicted large temperature changes with the application of electric or stress fields, and  even greater results with both fields combined, he said.


The prediction and fundamental understanding of such original multicaloric effect could potentially lead to new ways of exploiting the caloric effects and potentially advancing solid-state refrigeration, Lisenkov said.


To learn more about Lisenkov’s research, click here.