(V1-xAlx)(2)O-3 Ultrafine powders have been synthesized successfully by pyrolysizing poly-crystalline Al-doped precursor, Al-doped (NH4)(5)[(VO)(6)(CO3)(4)(OH)(9)]center dot 10H(2)O in H-2 atmosphere at 1373 K for the first time. The relation between the ratio of Al/V in the VOCl2 solution and that in polycrystalline Al-doped precursor was studied. The result shows that this chemical doping method is successful, and the Al (III) content in precursor is controllable. The lattice parameters of (V1-xAlx)(2)O-3 determined by XRD at room temperature and high-temperature reveal that the Al (III) enter the V2O3 lattice. The SEM micrograph shows that the size of the powder particles is about 100-200 nm. The DSC and magnetic susceptibility results of the (V1-xAlx)(2)O-3 demonstrate that the powders exhibit the intrinsic phase transition properties. (C) 2008 Elsevier Ltd. All rights reserved.