The dielectric properties of KCa2 Nan-3 Nb n O3n+1 (n=3-6) Dion-Jacobson homologous series have been investigated. The dielectric constants (ε) increase with the number of octahedral units (n), and the n=6 compound (KCa2 Na3 Nb6 O19) exhibits a stable dielectric response with ε=∼500 between 1 kHz and 1 MHz. This n -dependent behavior is similar to those observed in other layered perovskites such as Ruddlesden-Popper and Aurivillius phases. Raman scattering studies reveal that increase in n in KCa2 Nan-3 Nbn O3n+1 leads to higher polarizability of the lattice and softening of the lowest-frequency phonon mode, which is responsible for the observed enhancement in ε with n.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)