Wave Band Adjustable Infrared Filtering via Mott Transition of Nano Ti₂O₃

The Mott transition of Ti₂O₃ nano powders is systematically investigated. It is found that in the Mott transition of Ti₂O₃ nano powders, the infrared transmittance declines gradually with temperature rising. The curves of the infrared transmittance at the highest and lowest temperature present a “trumpet” shape ranging from 13.3 to 5.9 µm in wavelength. The “trumpet” feature of nano Ti₂O₃ can be applied to realize the large and adjustable wave band in infrared filtering. The filtering band covers from short to long wavelengths with temperature rising. The big difference in infrared transmittance at 13.3 µm is determined by grain size distribution.