Thermochromic and infrared emissivity characteristics of cobalt doped zinc oxide for smart stealth in visible-infrared region

摘要

Cobalt doped zinc oxide nanopowders were prepared via solid-state reaction. The influences of calcining temperatures on crystal structure, morphology, emissivity and color change of the Zn1-xCoxO nanopowders were studies detailedly. The results indicate that the substitute for Zn2+ by Co2+ in hexagonal wurtzite ZnO usefully sintering temperatures are 900-1200 degrees C. Moreover, the crystallinity, the oxygen vacancy content and the amount of Co substituted Zn(2+ )in the Zn1-xCoxO nanopowders are increasing with the heating temperature improving. All the samples show reversible thermochromism, which can reversible color change from green to yellow by rising test temperature from 25 to 800 degrees C. Meanwhile, the largest emissivity change is 0.321 as the test temperature changes between 25 and 800 degrees C in the sample heated at 1100 degrees C. The Zn1-xCoxO has great potential applications for smart adaptive camouflage in visible-infrared region.