Electrical Properties of Bismuth-Layered Structural Ca_xSr_2-xBi₄Ti₅O₁₈ Ceramics

Abstract

Effects of amount of Ca on crystal structure, microstructure, ferroelectric properties, and dielectric properties of the CaxSr2-xBi4Ti5O18 (CSBTi-x) ferroelectric ceramics were investigated. The results show that single-phase layered perovskite ferroelectrics were obtained and no appreciable secondary phase was found.Ca-doping results in a notable enlargement of remnant polarization 2Pr. The 2Pr of CSBT-0.15 reaches a large value, the remnant polarization 2Pr and coercive field 2Ec were 18.1µC/cm2 and 120.2kV/cm, respectively. Dielectric constant and dielectric loss of CSBT-0.15 was also measured, showing dielectric constant εr=199~194 and dielectric loss tanδ=0.02~0.014 over the range of 100 kHz~1MHz, respectively.

Raman scattering, microstructural and dielectric studies on Ba1−xCaxBi4Ti4O15 ceramics

“…Average grain size as well as the aspect ratio was found to increase with increasing Ca content indicating that the addition of Ca facilitates the grain growth. Similar change in the microstructure has been observed in Sr 2 Bi 4 Ti 5 O 18 where replacing Sr 2þ by smaller Ca 2þ cation increased the average grain size and aspect ratio [29]. …”

Effect of ZnSnO3 on dielectric and ferroelectric properties of Sr2Bi4Ti5O18 ceramics

“…However, when doped ions occupy A‐site (Sr +2 or Bi +3 ) cations in BLSFs compounds resulted in grain growth promotion. Grain growth promotion was extensively observed in the literature for the A‐site (Sr +2 or Bi +3 ) substitution in SBT ceramics 27,32,45,48 . This study indicates that the ZS doping in SBT acts as a gain growth inhibitor and indirectly suggests possible ions from doped ZS occupies only B‐site (Ti +4 ) cations of SBT.…”

“…Grain growth promotion was extensively observed in the literature for the A-site (Sr +2 or Bi +3 ) substitution in SBT ceramics. 27,32,45,48 This study indicates that the ZS doping in SBT acts as a gain growth inhibitor and indirectly suggests possible ions from doped ZS occupies only B-site (Ti +4 ) cations of SBT. The gain growth reduction in the case of SBT-10, SBT-20, and SBT-30 is mainly due to higher activation energy associated with the incorporation of SnO 2 and Zn 2 SnO 4 ceramics at the grain boundaries of SBT ceramics.…”