Impedance and electromechancial studies on Ca_0.1Sr_0.9La_xBi_2-xTa₂O₉ ceramics

ABSTRACT

Ca_0.1Sr_0.9La_xBi_2-xTa₂O₉ ceramics were synthesized through solid state double sintering route. Impedance, resonance and anti-resonance studies under clamped state were carried out on the prepared ceramics. The activation energy for relaxation is within the range 0.850–1.230 eV depending up on composition x. Equivalent circuit modelling was done to the experimental Cole-Cole data so as to obtain the grain, grain boundary resistance and capacitance. The activation energy for grain conduction increased with the increase of x value except for x = 0.05 ceramic composition. The activation energy for grain boundary conduction is lower for the ceramic compositions with lanthanum doped when compared to pure CSBT ceramic. The activation energy for grain and grain boundary conduction are within the range 0.748–1.338 eV depending up on composition x and temperature. The electromechanical coupling factors are above 0.9990 and vary in fourth decimal place with the increase of temperature and composition x. The electromechanical coupling factor decreased with the increase of x value.

KEYWORDS:

• Ca_0.1Sr_0.9Bi₂Ta₂O₉
• lanthanum doping
• impedance
• electromechanical coupling

Acknowledgments

Authors are thankful to DRDO, New Delhi for financial assistance.

Additional information

Funding

This work was supported by the DRDO, New Delhi.