Single-step combustion synthesis of YAlO3 powders

Single-phase YAlO3 was obtained by combustion synthesis using a fuel mixture of urea and glycine. Temperature–time profile recorded by infrared thermal imaging indicates that an aqueous solution of Y(NO3)3:Al(NO3)3:urea:glycine (molar ratio of 6:6:15:10) ignites at 315 °C, leading to the formation of a white nanocrystalline YAlO3 powder (51 nm) having a BET surface area of 3 m2/g. No additional annealing was required, as the formation of YAlO3 structure took place at the expense of the heat generated in situ by the highly exothermal, self-propagated combustion reaction. In this case, the maximum combustion temperature recorded during the combustion reaction was 1661 °C. Powders prepared under the same conditions but using the classical version of the combustion method, involving the use of a single fuel (urea or glycine), were amorphous. The absence of YAlO3 from these samples was caused by the lower temperature achieved during the combustion processes: 414 °C in the case of urea and 829 °C in the case of glycine.