Phys.org December 17, 2019
For most solids, the thermally emitted power increases monotonically with temperature in a one-to-one relationship that enables applications such as infrared imaging and noncontact thermometry. A team of researchers in the US (University of Wisconsin, Harvard University, Purdue University, MIT, Brookhaven National Laboratory) has shown that ultrathin samarium nickel oxide undergoes a fully reversible, temperature-driven solid-state phase transition. Its smooth transition enabled them to engineer the temperature dependence of emissivity to precisely cancel out the intrinsic blackbody profile for both heating and cooling. The design results in temperature-independent thermally emitted power within the long-wave atmospheric transparency window (wavelengths of 8 to 14 µm), across a broad temperature range of ∼30 °C, centered around ∼120 °C. According to the researchers the effect could include humans and vehicles presenting a future asset to stealth technologies…read more. Video TECHNICAL ARTICLE
A quantum material tricks an infrared camera by concealing the heat properties of an object that would give it away. Credit: Purdue University photo/Erin Easterling.