Friday, October 25, 2013

Material looks cool while heating up | Science News

Material looks cool while heating up | Science News:  The compound vanadium dioxide makes such a transition around 70o Celsius, switching abruptly from being an electrical insulator to a conductor...

... the researchers heated the vanadium dioxide-sapphire sample and, with an infrared camera, measured how much infrared light the sample emitted as it warmed. The color gradually shifted from blue to red as the sample's temperature increased from 60o to 74o, as is typical for a warming object. But then something strange happened: Even though the sample’s temperature continued to rise up to 100o, the camera readout returned to an icy blue and stayed there.