Sol–gel synthesis and infrared radiation property of Li-substituted cordierite

The Mg2−xAl4+1/2xLi1/2xSi5O18 (0.1≤x≤1) ceramics with the substitution of (Li1/2Al1/2)2+ for Mg2+ were synthesized by the sol–gel method. The characterization of the modified cordierite included X-ray diffraction, SEM, EDS and infrared radiation. The crystal structure of Mg2Al4Si5O18 with the substitution of (Li1/2Al1/2)2+ for Mg2+ changed and the amount of secondary phase increased with increasing the x value from 0.1 to 1. High infrared emissivity over 0.9 in the band of 8–14 μm at room temperature was obtained in Mg2−xAl4+1/2xLi1/2xSi5O18 (x=0.1). The material based on cordierite with x=0.1 sintered at 1200 °C maintained a single phase, compact microstructure and good infrared emissivity with potential use in infrared heating.