Preparation and characterization of (V1−xCrx)2O3 nano-powders by chemical doping method

(V1-xCrx)2O3 nano-powders have been synthesized successfully for the first time in powder form by pyrolising polycrystalline Cr-doped precursors, Cr-doped (NH4)5[(VO)6(CO3)4(OH)9]·10H2O in H2 atmosphere at 1373 K. Development of single-crystal of the Cr-doped precursor showed that Cr (III) possibly entered the precursor lattice or a solid solution formed in the precursor. Comparing the ratio of Cr/V in the raw materials (VOCl2 solution) to the Cr/V in the polycrystalline Cr-doped precursor indicated that the chemical doping method was feasible and Cr content in the precursor was controlled easily. The lattice parameters of Cr-doped V2O3 powders determined by X-ray diffraction (XRD) were consistent with those of single-crystalline Cr-doped V2O3, revealing that Cr (III) entered the V2O3 lattice. Both the results of differential scanning calorimetry (DSC) and magnetic susceptibility of the (V1−xCrx)2O3 demonstrated that the Cr-doped V2O3 powders exhibit intrinsic phase transition properties. Homogeneously distributed spherical (V1−xCrx)2O3 powders with a particle size of about 40 nm have been obtained.