Dielectric anomalies and compositional inhomogeneity of (K,Na,Li)NbO3 ceramics

KxNa(0.942−x)Li0.058NbO3 ceramic samples were prepared by the solid-state reaction method, and their crystal structures, wave dispersive spectra, and dielectric, ferroelectric, and piezoelectric properties were characterized. The chemical microdomains showed different compositional inhomogeneity, as indicated by the abnormal peaks from the temperature dependence of dielectric constants in the frequency range 102-106 Hz. The diversifications of abnormal peaks of dielectric constant and loss were explained by a space-charge model. During the phase transition, a contradictory community was proposed qualitatively between the effect of space-charge model with hopping cation by changing the frequency and that of current-carrier scattering by their structural transitions. Their co-contributions affected the changes in dielectric constants and loss. The consistent tendencies between the inhomogeneity of all cations in polymorphic chemical microdomains and lattice volumes and their ferroelectric and piezoelectric properties are discussed in this study.