Synthesis of Bi₂Cr_0.5Co_0.5Nb₂O_9+∆ Nanocrystalline Ceramics

The modified sol-gel method (Pechini method) is shown to synthesize multielement oxides on the basis of bismuth niobate that crystallize in the pyrochlore structure (space group Fd-3m). The temperature for the synthesis of a single-phase sample amounts to 950°C, which is 100°C lower than the calcination temperature used in the conventional ceramic method of synthesis. The average crystallite size determined radiographically varies from 39 nm (850°C) to 48 nm (1050°C) depending on the sintering temperature. According to x-ray diffraction analysis, the unit cell parameter is equal to 10.4872(6) Å. The conducted elemental mapping indicates a uniform distribution of metal atoms on the sample surface, while energy dispersive x-ray analysis shows that the chemical composition of the synthesized sample corresponds to the specified theoretical composition.