Crystal structure, spectroscopy, and thermal expansion of compounds in MI2O-Al2O3-TiO2 system

► Compounds in M2O-Al2O3-TiO2 systems have been prepared by solid-phase reactions. ► Crystal structures of four compounds were refined using the Rietveld method. ► Crystal-chemical systematics of compounds in M2O-Al2O3-TiO2 system was performed. ► Raman and IR investigation have been made. ► Thermal expansion coefficients of all compounds were determined.