Synthesis and dielectric properties of strontium substituted calcium niobate ceramics

Abstract

Layered perovskite KCa2(1x)Sr2xNb3O10 ceramic (x = 0, 0.2, 0.4, 0.6, 0.8 and 1) materials were prepared by a conventional solid-state reaction method, and the effects of Sr substitution for Ca on the crystal structure and dielectric properties of the KCa2(1x)Sr2xNb3O10 system were investigated. Also, potassium ions were exchanged with proton ions to obtain HCa2(1x)Sr2xNb3O10. Then, X-ray diffraction, infra-red spectra, and energy dispersive detector analysis were carried out to verify immaculate substitution. Unlike alkali cations intercalated powder, the dielectric properties of 2Ca(1x)SrxNb2O6–Ca2(1x)Sr2xNb2O7 mixtures, which were obtained from HCa2(1x)Sr2xNb3O10 by sintering, showed high dielectric permittivity with increasing amounts of strontium, and remained unaffected by frequency change from 1 kHz to 1 MHz. Its compositional dependence behavior was analyzed through Raman spectral analysis. X-ray diffraction, differential thermal analysis, and thermogravimetry observation revealed the phase transition on sintering of HCa2(1x)Sr2xNb3O10. 2014 Elsevier B.V. All rights reserved.