SYNTHESIS OF NANOCRYSTALLINE COMPLEX OXIDES IN SUPERCRITICAL ALCOHOLS
Ключевые слова:synthesis in supercritical alcohols, complex oxides, lanthanum orthoniobate.
An intensive search for solid electrolytes with high proton conductivity is being continued over the
past few decades, which is primarily due to the high practical significance of these systems. Proton conductors are
widely used as components of electrochemical devices such as gas sensors, electrolyzers, fuel cell membranes, etc.
The variety of currently known solid proton conductors can be classified by operating temperature parameters, with
the allocation of low, medium and high temperature regions. Each class, from the point of view of its practical use,
has a number of advantages, but at the same time, specific disadvantages that hinder practical implementation. In this
regard, the material science goal - the synthesis of new materials with functional properties, remains relevant.
For the first time, complex oxides – lanthanum niobates – were synthesized using alcohol solutions of salts of
the corresponding metals by the solvothermal method in a flow reactor in a supercritical isopropanol medium. This
method allows one to obtain single-phase lanthanum orthioniobate oxides, the phase composition, structure and
morphology of which is characterized by X-ray phase analysis (XRD), Raman spectroscopy (Raman spectroscopy),
scanning and transmission electron microscopy (SEM and TEM).