Low-temperature synthesis of ultrafine Cr,Mg-codoped Al2TiO5 nanocrystals as high-temperature green ceramic pigment

Tialite (Al2TiO5) is attracting as a high-temperature ceramic host matrix, but the decomposition of Al2TiO5 at 780–1280 °C is a serious obstacle for practical application. Herein we prepared successfully ultrafine Cr,Mg-codoped Al2TiO5 green ceramic pigment with the nanocrystal sizes less than 50 nm and high-temperature stability of up to 1200 °C via nonhydrolytic sol-gel (NHSG) method followed by heating treatment of 750 °C. The effects of Cr and Mg content on phase composition, crystal structure, thermal stability and color property were well investigated. The optimum Cr,Mg-codoped Al2TiO5 pigment with 20 mol% Mg and 6 mol% Cr exhibited an excellent green color (L* = 76.94, a* = −9.62, b* = 14.17), which can be reasonably maintained in exposed air by a heating treatment at 1200 °C for 10 h or in transparent ceramic glaze at 1200 °C for 30 min. These enhanced performances were mainly attributed to synergistic effect of Cr and Mg doping, which hindered the tendency of Al2TiO5 toward decomposition, indicative of its potential application in high-temperature ceramic decoration.