Solid-state synthesis, characterization, and properties of Ni4Nb2O9-based solid solutions

In this paper, we report the solid-state synthesis, characterization, and physicochemical properties of Ni 4– x Zn x Nb 2 O 9 ( x = 0, 0.1, 0.3, 0.5, 0.75, 1.0) zinc-containing nickel niobates and Ni 4 Nb 2– x Ta x O 9 ( x = 0.1, 0.3, 0.5, 1.0, 2.0) solid solutions. The materials were characterized by X-ray diffraction. We determined the particle size composition of the synthesized powders, assessed their chemical stability in acid media, obtained IR spectra of the solid solutions, and measured their electrical conductivity as a function of temperature. Some of the solid solutions were used to fabricate and characterize nickel-selective electrodes, which were successfully tested in ion-selective measurements.