Effect of annealing time and annealing atmosphere on infrared emissivity property of Zn1-xCoxO by solid state reaction

Abstract

The Zn 1-x Co x O powders were synthesized by solid-state reaction at different annealing time and annealing atmosphere. The effects of annealing time and annealing atmosphere on the structure, morphologies and infrared emissivities have been investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible absorption spectroscopy and IR-2 dual-band infrared emissometer. The results indicate that the Zn 1-x Co x O samples have hexagonal wurtzite structure while the peaks of the secondary phase, Co, were observed when sintering at N 2 atmosphere. The annealing time and annealing atmosphere have important impacts on the microstructure and the infrared radiation properties of Zn 1-x Co x O nanopowders. UV-visible absorption spectra showed that Co ions substituted the Zn ions in the ZnO lattices. And the infrared emissivity depends on the microstructure, grain size and lattice vibration.