Synthesis and characterization of nanoscale Bi₂Cu _0.1V_0.9O_5.35 powders by solution-based chemical methods

Nanocrystalline Bi₂Cu_0.1V_0.9O _5.35 (BCVO) powders were synthesized by solution-based chemical methods. Materials have been characterized by the thermogravimetric analysis, X-ray diffraction, and scanning/transmission electron microscopy. The sintering temperatures to complete phase transition are above 330 °C, 320 °C and 470 °C for the primary powders obtained by the sol-gel technique, an ethylenediaminetetra acetate-citrate combustion gel route and a modified reversing titration co-precipitation method (RP), respectively, which were much lower than the 600 °C required by conventional solid state method (SS). The powders synthesized by EC with 2 wt. % of surfactant, polyethylene glycol PEG 4000 have rather a narrow size distribution, within 30-50 nm, and as the PEG 4000 content increases, they form agglomerates irregular in shapes. In RP the optimal concentration of PEG 4000 is about 5 wt. % and the average grain size of the sample is 20 nm. The modified reaction in homogeneous solutions can be controlled to produce uniform BCVO nanoparticles.