Probing the dielectric behavior of lead-free BCST ceramic composite: An impedance spectroscopic approach. (2022) - Chitra,
Highlights: (Ba1-x Cax ) (Ti1-y Sny )O3 (BCST) (0.06 ≤ x ≤ 0.18, 0.04 ≤ y ≤ 0.08) ceramics were prepared. Very high & frequency invariant RT dielectric constant obtained at higher BST ratio. Equivalent circuit fitted for each composition showing grain bulk & boundary effect. Electrical response of ceramics was successfully demonstrated by these circuits. Frequency-independent BCST3 properties makes it useful as RF dielectric substrate. Abstract: Recently developedlead-free candidate, (Ba1-x Cax ) (Ti1-y Sny )O3 (BCST) ceramics were synthesized using conventional sintering route. Extraordinarily frequency independent high dielectric propertiesexhibited by BCST composition with large BST proportion. Complex Impedance Spectroscopy technique establishes the relationship between microstructure of the system and the frequency dependence of various relaxation processes involved. Non-Debye type relaxation exists in all BCST samples except BCST3 (x = 0.12, y = 0.06), supported by Cole-Cole plots. Equivalent circuits were modeled containing minimum RC elements representing grain bulk and boundaries contribution to electrical response. Frequency-independent high dielectric constantwith low loss of BCST3 makes it suitable as RF dielectric substrate and dielectric filters.