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

The Mg 2− x Al 4+1/2 x Li 1/2 x Si 5 O 18 (0.1≤ x ≤1) ceramics with the substitution of (Li 1/2 Al 1/2 ) 2+ for Mg 2+ 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 Mg 2 Al 4 Si 5 O 18 with the substitution of (Li 1/2 Al 1/2 ) 2+ for Mg 2+ 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 Mg 2− x Al 4+1/2 x Li 1/2 x Si 5 O 18 ( 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.