Due to environmental concerns much of the current research has been oriented towards lead-free materials.Alkali niobates have been studied as a potential replacement for lead-based piezoelectric ceramics.Problems related to synthesis and sintering of alkali niobates are connected to assumed deficiency of alkalines stemming either from hygroscopicity of the alkali reagents,and/or from sintering where alkali losses could be evidenced by the appearance of secondary niobium-rich phases.