Controllable synthesis of ZnO with different morphologies and their morphology-dependent infrared emissivity in high temperature conditions

Nowadays, the high temperature low infrared emissivity problem has been of increasing significance and attracting more attention owing to the widespread applications for high temperature conditions. One key solution for this problem is to study the mechanism of high temperature low infrared emissivity and then design the materials with low infrared emissivity at elevated temperature. This paper gives an introduction to the infrared emissivity of ZnO powders in 3∼5 μm waveband at elevated temperature with various well-defined morphologies, e.g. needle-, pencil-, flower-, and flat-like. Among these morphologies, flat-like ZnO powders exhibit the lowest infrared emissivity because they have the largest real part of the dielectric function. Additionally, the variation of electrons average scattering time and lattice vibration at various temperature determine the variation tendency of infrared emissivity with temperature.