Thermal stable BaAl2O4 nanocrystallites with pure spinel structure was successfully prepared at 650degreesC using amorphous BaAl2(DTPA)(1.6)(H2O)(3) as precursor. The crystallization temperature via this synthesis way was about 500degreesC lower than that via traditional methods, such as sol-gel synthesis and solid-state reactions. The precursor was synthesized by simple inorganic reaction and can be decomposed into BaAl2O4 species at the temperature below. 500degreesC, which was proved by DTA-TGA and X-ray photoelectron spectroscopy. X-ray diffraction results illustrated that BaAl2O4 crystal phase can be formed at 650degreesC with crystal size less than 60 nm. Especially, the crystal size increased weakly with either promoting the calcination temperature or prolonging the sintering time, indicating the high thermal stability of this material. The grain size was approximately 60 nm and the surface area was 10.88 m(2)/g. (C) 2003 Elsevier Science B.V. All rights reserved.